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S0001457520312471 | The motivation of this research is to understand tourists aberrant driving behaviors while traveling by car and explore the factors related to these behaviors . A questionnaire that measures driving behaviors driving attitudes driving skills and personal attributes was implemented via the Internet . Through factor analysis a four factor structure of tourists aberrant driving behaviors was obtained . The result indicates that tourists unsafe driving behaviors have different characteristics from unsafe driving behaviors in daily travel with a higher frequency of behaviors related to environment carelessness and fatigue driving . The main cause of these behaviors is drivers attitude rather than skill and personal attribute . When drivers reported themselves good at staying focused behaviors subject to Carelessness were found to increase as there is a more approving attitude towards careless driving among those drivers . | A new DBQ is developed to obtain the characteristics of tourists aberrant driving behavior ADB. A four factor structure is extracted from tourists ADBs by factor analysis. Tourists ADBs have different characteristics from ADBs in daily travel. Attitude has significant impact on tourists ADBs rather than attributes and skills |
S0001457520315591 | Driving a vehicle requires individuals awareness of their surroundings to prevent collisions with other vehicles objects and pedestrians . While previous research has investigated time to arrival in real world and simulated driving situations there is little information on how pedestrian reflectance and time of day impact TTA . The present study investigated how vehicle velocity viewing time pedestrian reflectance and time of day affected individuals estimates of TTA . We used recorded driver perspective footage of a vehicle approaching simulated pedestrians at different velocities during daytime and nighttime . We found that TTA was consistently underestimated with the most accurate TTA estimates occurring at the lowest vehicle velocity . We also found TTA accuracy was better during daytime conditions . Pedestrian reflectance did not produce a significant main effect but it did interact significantly with both velocity and time of day . These results suggest that multiple variables are responsible for TTA estimation . A better understanding of what factors may affect TTA estimates helps both researchers who investigate the phenomenon and laypersons who strive for safe driving practices . | Time of day vehicle velocity pedestrian reflectance and viewing time all interacted to influence TTA estimates. On average TTA was underestimated at all vehicle velocities. TTA estimates were most accurate at the lowest vehicle velocity. TTA was more underestimated in nighttime conditions compared to daytime conditions. |
S0001457520315608 | No economic evaluations exist of free or subsidized ridesharing services designed to reduce impaired driving . To evaluate the effects and economics of a 17 weekend program that provided rideshare coupons good for free one way or round trips to from the hospitality zones in Columbus Ohio coupled with a modest increase in enforcement and a media campaign that used messaging about enforcement to promote usage . Web surveys of riders and intercept surveys of foot traffic in the hospitality zones yielded data on the reduction in driving after drinking and the change in alcohol consumption associated with coupon use . We estimated crash changes from trip data using national studies then confirmed with an ARIMA analysis of monthly police crash reports . Costs and output data came from program and rideshare company records . 70.8 of 19 649 responding coupon redeemers said coupon use reduced the chance they would drive after drinking . An estimated 1 in 4 310 drink driving trips results in an alcohol attributable crash so the coupons prevented an estimated 3.2 crashes . Consistent with that minimal change the ARIMA analysis did not detect a drunk driving crash reduction . Self reports indicated alcohol consumption rose by an average of 0.4 drinks per coupon redeemer possibly with an equal rise among people who rode with the redeemer . The program cost almost 650 000 and saved an estimated 1.8 years of healthy life . Across a range of discount rates and values for a year of healthy life it cost 366 000 to 791 000 per year of healthy life saved . Its estimated benefit cost ratio was between 0.31 and 0.59 meaning it cost far more than it saved . Ridesharing coupled with a media campaign and increased enforcement was not a cost effective drunk driving intervention . Although it reduced drink driving crashes and saved years of healthy life those savings were modest and expensive . Moreover the self reported increase in participant drinking imposed countervailing risks . Even sensitivity analyses that potentially overestimate the benefits and underestimate the costs indicate a significant imbalance between program costs and savings . Any funding devoted to ridesharing would divert scarce resources from interventions with benefit cost ratios above 1 . Thus our evaluation suggests that governments should not devote energy or resources to ridesharing programs if their primary objective is to reduce drink driving or harmful alcohol use . | Well publicized free safe rides to from hospitality zones reduce drink driving. These rides increase alcohol consumption and cost more than they save. Limiting rides to one way from the zones does not change these findings. Return on investment would rise for drink driving crash rates above US rates. US governments should not devote energy or resources to ridesharing programs. |
S000145752031561X | The proliferation of Advanced Vehicle Technologies has generated both excitement and concern among researchers policymakers and the general public . An increasing number of driver assistance systems are already available in todays automobiles many of which are expected to become standard . Therefore synthesizing the available evidence specific to the safety of AVTs is critical . The goal of this scoping review was to summarize this evidence with a focus on AVTs that require some driver oversight levels of automation taxonomy . | A scoping review of evidence from 324 studies of AVTs from 25 countries was conducted. Most studies involved mixed age groups 51 and occurred in driving simulators 70 . Longitudinal control 50 and driver reaction time 40 were the most common objective measures. Trust 27 and driver workload 20 were the most common subjective measures. Experimental testing of AVTs should detail driver demographics and corresponding effect on safety. |
S0001457520315621 | Driving under the influence is illegal in the United States because a drivers mental and motor skills can be seriously impaired by alcohol or drugs . Consequently DUI violators involvement in severe crashes is high . Motivated by the spatial and temporal nature of traffic crashes this study introduces an integrated spatio temporal approach to analyzing highway safety data . Specifically this study estimates Geographically and Temporally Weighted Regression models to understand the consequences of DUI in crashes . GTWR can theoretically outperform traditional regression methods by accounting for unobserved heterogeneity that may be related to the location and time of a crash . Using Southeast Michigan crash data this study finds that DUI is associated with a 25 higher likelihood of injury in a crash . The association between injury severity and DUI varies significantly across space and time . From the spatial aspect DUI crashes in rural or small town areas are more likely to cause injuries than urban crashes . From the temporal aspect different times are associated with varying relationships between injury severity and DUI . If focusing on DUI crashes in late nights and early mornings on Fridays the entire northeast part from Clinton Charter Township to Port Huron is associated with severer injuries than other regions including Detroits urban area and its south . On Mondays the DUI crashes in the northwest are also more likely to cause severe injuries . The methodology introduced in this study takes advantage of modern computational tools and localized crash inventory data . This method offers researchers and practitioners an opportunity to understand highway safety outcomes in great spatial and temporal details and customize safety countermeasures for specific locations and times such as saturation patrols . | This study revisits the relationship between injury severity and DUI in crashes. This study introduces a spatiotemporal modeling approach to model injury severity in crashes. The approach uncovers the spatiotemporally varying correlates of injury severity. The relationship between injury severity and DUI varies significantly across space and time. This study offers insights to customize safety countermeasures for specific locations and times. |
S0001457520315633 | Although the enforcement of seatbelt use is considered to be an effective strategy in reducing road injuries and fatalities lack of seatbelt use still accounts for a substantial proportion of fatal crashes in Tennessee United States . This problem has raised the need to better understand factors influencing seatbelt use . These factors may arise from spatial temporal characteristics of a driving location type of vehicle demographic and socioeconomic attributes of the vehicle occupants driver behaviours attitudes and social norms . However the above factors may not have the same effects on seatbelt use across different individuals . In addition the behavioural factors are usually difficult to measure and may not always be readily available . Meanwhile residential locations of vehicle occupants have been shown to be associated with their behavioural patterns and thus may serve as a proxy for behavioural factors . However the suitability of geographic and residential locations of vehicle occupants to understand the seatbelt use behaviour is not known to date . | The home address of vehicle occupants can be used as a proxy to their behaviour. Determinants of seatbelt use have varied effects across drivers in Tennessee. Drivers are categorized to eccentric and conformist groups based on their behaviour. Males young age and drug consumption are negatively associated with seatbelt use. Population density travel time and income per capita contribute to seatbelt use. |
S0001457520315645 | The estimation of the effect of contributors to crash injury severity and the prediction of crash injury severity outcomes suffer often from biases related to missing data in crash datasets that contain incomplete records . As both estimation and prediction would greatly improve if the missing values were recovered this study proposes a sequential approach to handle incomplete crash datasets and rank contributors to the injury severity of crashes on mountainous freeways in China . The sequential approach consists of two parts multivariate imputation by chained equations imputes the missing values of independent variables a random forest classifier analyses the correlation between the dependent and the independent variables . The first part considers different imputation methods in light of the independent variables being either binary categorical or continuous whereas the second part classifies the correlations according to the random forest classifier . The proposed method was applied to the case study about mountainous freeways in China and compared to the analysis of the raw dataset to evaluate its effectiveness and the results illustrate that the method improves significantly the classification accuracy when compared with existing methods . Moreover the classifier ranked the contributors to the injury severity of traffic crashes on mountainous freeways in order of importance vehicle type crash type road longitudinal gradient crash cause curve radius and deflection angles . Interestingly a lower importance was found for environmental factors . | Sequential method from statistics and machine learning. Multivariate Imputation for different types of variables. Random Forest Classifier for crash injury severity analysis. High efficiency when compared to commonly used imputation methods. Ranking of factors contributing to injury severity on Chinese mountainous highways. |
S0001457520315669 | This study addressed the causal ordering problem in deterrence research by examining the perceptual stability of deterrence variables over time and comparing the results via cross sectional and longitudinal surveys . This research extends upon scant previous research by including three key classical deterrence variables as well as Homels extra legal deterrence related variables of the fear of physical loss material loss and social sanctions . A longitudinal survey design was utilised over a three month time period | Longitudinal study assessed stability of road safety deterrence related perceptions. Stability of both legal and non legal perceptions was assessed over 3 months. Fluctuations were found in all deterrence related perceptions. Certainty of apprehension had the largest fluctuation. Implications for methodology used in road safety deterrence studies. |
S0001457520315670 | The effect of mandated societal lockdown to reduce the transmission of coronavirus disease 2019 on road traffic accidents is not known . For this reason we performed an in depth analysis using data from Statewide Traffic Accident Records System . We reviewed data on total 2292 road traffic accident records in Missouri from January 1 2020 through May 15 2020 . We treated March 23 as the first day of mandated societal lockdown and May 3 as the first day of re opening . We have found that there was a significant reduction in road traffic accidents resulting in minor or no injuries but not in accidents resulting in serious or fatal injuries after mandated societal lockdown . Furthermore there was a significant reduction in road traffic accidents resulting in minor or no injuries after the mandated social lockdown in the time series analysis . There was an increase in road traffic accidents resulting in minor or no injuries after expiration of mandatory societal lockdown . The mandated societal lockdown policies led to reduction in road traffic accidents resulting in non serious or no injuries but not those resulting in serious or fatal injuries . | Mandated societal lockdown in Missouri reduced the rate of road traffic accidents. No changes in road traffic accidents resulting in serious or fatal injuries. Increased road traffic accident related hospitalizations are not expected. |
S0001457520315682 | In conditionally automated driving drivers have difficulty taking over control when requested . To address this challenge we aimed to predict drivers takeover performance before the issue of a takeover request by analyzing drivers physiological data and external environment data . We used data sets from two human in the loop experiments wherein drivers engaged in non driving related tasks were requested to take over control from automated driving in various situations . Drivers physiological data included heart rate indices galvanic skin response indices and eye tracking metrics . Driving environment data included scenario type traffic density and TOR lead time . Drivers takeover performance was categorized as good or bad according to their driving behaviors during the transition period and was treated as the ground truth . Using six machine learning methods we found that the random forest classifier performed the best and was able to predict drivers takeover performance when they were engaged in NDRTs with different levels of cognitive load . We recommended 3 s as the optimal time window to predict takeover performance using the random forest classifier with an accuracy of 84.3 and an F1 score of 64.0 . Our findings have implications for the algorithm development of driver state detection and the design of adaptive in vehicle alert systems in conditionally automated driving . | We develop a model to predict takeover performance in Level 3 automated driving. The model predicts takeover performance when drivers have an NDRT with varying load. We recommend 3 s as the optimal time window to predict takeover performance. We identify important physiological features for takeover performance prediction. |
S0001457520315694 | Traffic fatalities are the second cause of violent deaths in Colombia . However due to the signing of the peace agreement and the growing number of fatalities in road crashes it is possible that soon traffic fatalities will be the primary cause of violent deaths in the country particularly in urban areas . This study is an exploratory analysis focused on identifying the main factors associated with the severity of traffic crashes in urban areas using Cartagena as a case study . We analyzed three levels of crash severity namely fatal injury and property damage only considering factors in several different dimensions victim vehicle road infrastructure traffic and control day and time and environmental factors . A modeling approach based on multinomial ordered discrete models was used to properly identify the main factors associated with the severity levels . We found that the probability of fatal accidents is higher on streets with speed limits over 40km h and that males and people aged 60 years or older are the victims with the most significant risk of fatal crashes . Motorcycles were also identified as vehicles with the highest probability of fatal crashes in the city . We showed that the probability of fatal crashes occurring is higher on streets where pedestrian bridges traffic lights and crosswalks are present . These findings are worthy because in Colombia and other developing countries the authorities normally expect to reduce the probability of fatal accidents through investments in pedestrian bridges signaling devices and crosswalk markings . However according to our results it possibly will not occur unless further countermeasures are taken . Based on these findings reducing speed limits operational improvements at signalized intersections zero tolerance for traffic violations related to pedestrians an awareness campaign on pedestrian safety focused on males and people aged 60 or older and improving motorcycle safety are the countermeasures we proposed . Furthermore as the authorities make significant efforts to investing in pedestrian bridges we propose a further investigation into the traffic crashes in streets where there is this infrastructure since more severe events occur near them . | We analyze 2 339 crashes recorded in Cartagena Colombia. We focus on fatal injury and property damage only traffic crashes. Factors relating to victim vehicle road infrastructure traffic and control day and time and environment were considered. Probability of fatal crashes is higher near to pedestrian bridges traffic lights and crosswalks. |
S0001457520315700 | While cyclist aggression is relatively rare it has been associated with increased crash risk . Previous measures of cyclist aggression have not taken into consideration who the recipient of the aggression may be this is likely to differ across road user types . The aim of this study was to understand if cyclists aggression differs according to whether the recipient is a driver pedestrian or another cyclist . To examine this 1206 cyclists completed the Cycling Anger Expression Inventory CAX | Cyclists aggression toward drivers cyclists and pedestrians was examined. Aggression frequencies were compared across different recipients using the CAX. Cyclists had more frequent aggression toward drivers than cyclists or pedestrians. The CAX could be adapted to specific cyclist driver interactions. |
S0001457520315712 | A meta analysis was performed to review the potential effects of reversible lanes on traffic safety . A systematic review resulted in ten U.S studies with 155 estimates of safety effects that were selected for inclusion in the analysis . These studies employed either a simple before after comparison or a cross sectional comparison methodology . Study results were extracted by transforming the collision rates and frequencies of these studies into a log odds ratio . | Collision odds associated with reversible lanes appear to be higher overall for all study effect estimates combined. Collision odds were also higher for property damage only collisions injury collisions and peak period collisions. Meta regression showed that presence of left turn restrictions delineator correlated with a decrease in crashes. Presence of dynamic traffic control and static traffic control were both correlated with an increase in crashes. Cross sectional comparative studies also tended to find greater effects than simple before after studies. |
S0001457520315724 | Benchmarking performance monitoring progress and then recalibrating interventions is widely recognized as a valuable process for achieving continuous improvement in road safety . In this study a systematic and effective methodology IV VIKOR with FNBC is developed to perform the benchmarking of road safety development in an integrative manner for OECD countries . Linking to other methods and measures as the references 36 OECD Member countries are ranked and grouped into several classes based on their overall achievement regarding road safety from the past decade . This provides government officials and policymakers across the OECD Member countries with a flexible tool to comprehensively benchmark road safety development . Providing the ability to identify delays in action plan implementations and proactively redistribute resources toward more effective measures where required . Such a tool can also serve to increase political will and stakeholder accountabilities at the highest level of government and the private sector for all OECD members Thereby keeping the implementation of action plans on schedule . It helps OECD Member countries to establish the capacity for sustainable safety management supporting them in developing future strategies and reforms to create better policies for better lives . | Develop an easy to adapt model for benchmarking road safety development at the regional level. Report road safety development across the OECD member countries over the past decade. Provide the OECD with a step by step paradigm to strengthen the capacity for sustainable safety management. Support policymakers in charting informed future strategic directions and policy reforms for road safety improvement. Encourage governments with the increased political will to create a road transport system that maximizes safety. |
S0001457520315736 | Inexperienced drivers have a higher crash risk than others particularly at night when drivers of all ages are at increased risk but there has been little if any research on day night differences in drivers perceptions of risk and difficulty . Also previous research on determinants of risk and difficulty ratings has focused largely on effects of vehicle speed and researchers have identified a need to look more broadly at how ratings are affected by the complexity of depicted road traffic situations . | Young drivers varying in experience and age rated videos for risk and difficulty. Ratings were higher for night time videos than daytime ones. Ratings appeared to be influenced by the required rate of information processing. Risk and difficulty were highly correlated but empirically distinct variables. Neither driving experience nor age affected ratings. |
S0001457520315748 | Determining the impact of driver monitoring technologies to improve risky driving behaviours allows stakeholders to understand which aspects of onboard sensors and feedback need enhancement to promote road safety and education . This study investigates the influence of camera monitoring on Heavy Goods Vehicle drivers risky behaviours . We also assess whether monitoring affects individual driving events further when coupled with safe driving practices coaching . We evaluate the outcome of those practices on three telematics incidents heavily reliant on driving errors and violations i.e . the number of vehicle harsh braking harsh cornering and over speeding incidents . The objective is to understand how frequently individual incidents caused by risky driving behaviour occur without camera monitoring and without any coaching after camera installation and after camera installation and coaching . We investigate two commercial HGV companies with 263 and 269 vehicles respectively over a 16 months period from which the first 8 months contain data collected before the installation of cameras and the rest of the dataset contains incident counts after the installation of cameras . Company 1 provides coaching during the intervention phase while Company 2 does not offer coaching . Our analysis considers the baseline and the intervention phases during the same seasons to eliminate any possible bias due to the influence of weather on driving behaviour . Results show an overall significant reduction in the mean frequency of harsh braking incidents from baseline to intervention by 16.82 in Company 1 and 4.62 in Company 2 and a significant reduction in the mean frequency of over speeding incidents from baseline to intervention by 34.29 in Company 1 and 28.13 in Company 2 . Furthermore the effect of coaching has a significant difference in reducing the frequency of harsh braking | Monitoring and coaching Heavy Goods Vehicle HGV drivers significantly reduces their harsh braking and over speeding incidents. The number of harsh braking and harsh cornering incidents decrease more by monitoring and coaching than just monitoring without coaching. Seasonal changes can influence HGV risky driving behaviours. The causes of intentional driving violations are difficult to capture using camera monitoring. As drivers are made aware of their monitoring they become conscious and reduce their risky behaviours. |
S000145752031575X | The objectives of this paper were to directly examine the roles of central and peripheral vision in hazard perception and to test whether perceptual training can enhance hazard perception . We also examined putative cortical mechanisms underpinning any effect of perceptual training on performance . To address these objectives we used the gaze contingent display paradigm to selectively present information to central and peripheral parts of the visual field . In Experiment 1 we compared hazard perception abilities of experienced and inexperienced drivers while watching video clips in three different viewing conditions . Participants visual search behaviour and cortical activity were simultaneously recorded . In Experiment 2 we determined whether training with clear central and blurred peripheral vision could improve hazard perception among non licensed drivers . Results demonstrated that information from central vision is more important than information from peripheral vision in identifying hazard situations for screen based hazard perception tests clear central and blurred peripheral vision viewing helps the alignment of line of gaze and attention training with clear central and blurred peripheral vision can improve screen based hazard perception . The findings have important implications for road safety and provide a new training paradigm to improve hazard perception . | A new form of perceptual training that involved watching videos from a hazard perception driving test while eye tracking technology selectively blurred out peripheral areas of the visual field. An interdisciplinary approach by recording eye movement and brain activity. Blurring the peripheral parts of hazard perception training clips can help to effectively direct the attention of learner drivers during screen based hazard perception tests. Gaze contingent viewing and precise feedback and scoring systems can improve current hazard perception training interventions. |
S0001457520315761 | Eco safe driving is a promising approach to improve road safety while reducing transport emissions . The application of an eco safe driving system is feasible with the support of vehicle to vehicle infrastructure technologies . To guarantee system usability and safety appropriateness a key precondition is to ensure that driver mental workload and visual demands required for using the system are reasonable . This study explored how drivers mental workload and visual demands were affected when driving with an eco safe driving HMI . Four in vehicle eco safe HMI information conditions were evaluated including baseline advice only feedback only and advice feedback . Two traffic scenarios were simulated using an advanced driving simulator . Behavioural variables visual variables and subjective workload scores were collected from 36 licensed Australian drivers . The experiment results showed that the HMI prompted drivers to apply a smooth and stable brake force when they approached the intersection and a smooth acceleration when they left the intersection . Drivers mental workload indicated by visual measurements were consistent with their subjective reported workload levels . Drivers had a higher mental workload when they received and processed additional eco safe information in the advice feedback condition . An increase in mental workload induced by the in vehicle cognitive task initiated more blink activities while the increase in visual demand caused by a complex road situation led to blink inhibition . The study shows the HMI could significantly promote eco safe driving behaivours without causing excessive mental and visual workload of drivers . | Mental workload and visual demand when using an eco safe HMI system were studied. Blink variables and pupil size in different eco safe HMI conditions were analysed. The use of HMI system increased mental workload but within a reasonable level. High visual demand induced by road environment could lead to blink inhibition. Blink measures can be used as valid mental workload and visual demand indicators. |
S0001457520315785 | This study aimed to determine the risk factors associated with unsafe events involving a motor vehicle that occurred while group riding in Perth Western Australia . Naturalistic video footage was collected from 52 group riders and unsafe events identified . A case crossover study was used to compare the road infrastructure and group behavioural characteristics of 108 case sites where unsafe events occurred to 216 control sites where no unsafe events occurred . After controlling for potential confounding factors roundabouts increased the risk of an unsafe event compared to midblocks 3.63 95 confidence interval 1.578.42 | A naturalistic study examined risk factors for unsafe events while group riding. Roundabouts increased the risk of an unsafe event involving a motor vehicle. Traffic islands speed limits 60 km h and rider violations also increased risk. Riding 2 abreast in a traffic lane or with all riders in a bike lane decreased risk. Road infrastructure treatments and education could promote safety for group riders. |
S0001457520315797 | Random parameters model has been demonstrated to be an effective method to account for unobserved heterogeneity that commonly exists in highway crash data . However the predefined single distribution for each random parameter may limit how the unobserved heterogeneity is captured . A more flexible approach is to develop a random parameters model with heterogeneity in means and variances by allowing the mean and variance of potential each random parameter to be an estimable function of explanatory variables . This burgeoning technique for modelling unobserved heterogeneity has been increasingly applied to various safety evaluation scenarios recently . However the predictive performance of this emerging method which determines the practicability of the model for a specific circumstance has never been investigated as far as our knowledge . In addition the explanatory power by including heterogeneous means and variances of random parameters need to be further investigated to confirm the potential merits of this method in crash data analysis . | A random parameters model with heterogeneity in means variances was estimated. The negative binomial model was more reliable in general for safety analysis. Allowing heterogeneous means variances of random parameters offered more insights. Interactive effects of safety factors on crash frequency were concluded. fold cross validation method was used to assess the predictability. |
S0001457520315803 | In this paper the potential of using Augmented Reality technology to improve the safety of pedestrian crossings was tested by means of virtual information provided to a driver approaching a zebra crossing area . To achieve this objective a driving simulator study was carried out . The effectiveness of the system was tested and the results of the developed simulation tests with and without AR warning to inform the driver of a pedestrian crossing ahead were compared . Specifically AR warnings were tested under two different situations a visible pedestrian crossing the roadway and a non visible pedestrian made invisible by certain obstacles and who is about to cross the roadway . Two different virtual warnings were tested in both cases on a sample of forty six participants a flashing red arrow above the pedestrian and the same visual warning but with an additional audible warning system . The effects of the audible warnings were studied by comparing the driving performances and surrogate safety measures and Time to Zebra with those recorded under reference conditions . Positive effects of AR were observed . Specifically when the AR warnings were activated drivers started to decelerate well before the pedestrian crossing with a low deceleration rate and high TTC and TTZ . This study confirmed the great benefits that AR and connected vehicle technologies could bring to the overall safety conditions on the road network especially under risky situations and difficult maneuvers . The driving simulator is certainly an effective solution for studying and evaluating such technologies as well as studying their impact on driving performance . | Data crashes show that more than 280 000 victims of road crashes are pedestrians. The majority of road crashes are caused by poor driver oversight of road users. Augmented Reality technology could enable future systems to detect dangers earlier. Several AR video and audio warnings are tested in a driving simulator study. AR effectiveness in improving the safety of pedestrian crossings is demonstrated. |
S0001457520315815 | The goal of the current study was to develop a method to estimate whole body injury metrics which measure the overall impact of injuries using stochastic injury prediction results from a computational human surrogate . First hospitalized pedestrian data was queried to identify injuries sustained by pedestrians and their frequencies . Second with consideration for an understanding of injury mechanisms and the capability of the computational human surrogate the whole body was divided into 17 body regions . Then an injury pattern database was constructed for each body region for various maximum abbreviated injury scale levels . Third a two step Monte Carlo sampling process was employed to generate | A method was developed to estimate whole body injury metrics from injury risk. The estimated values were close to those from inpatient pedestrian data. The proposed method can simplify a vehicle design optimization process. The proposed method can be applied to various human surrogates. |
S0001457520315827 | Teen drivers are overrepresented in motor vehicle crashes and most studies concluded it was mainly due to their lack of experiences and tendencies of risk taking . The design of advanced driving assistance systems aims to provide assistance in multiple stages in human information processing during driving including environmental sensing information processing decision making and vehicle controlling in order to improve driving safety . It is expected that novice drivers may benefit more from using ADAS than adult drivers as such technologies can compensate for their frequent errors . This study examined whether and how an integrated crash warning system impacted on drivers following behavior and what were the corresponding age related differences through an analysis of two unique naturalistic driving study datasets . Significant age related differences in car following behavior were found . Results showed potential negative effects of ADAS on teen drivers following behavior that teen drivers tended to have less controlled pedal use during treatment weeks with ADAS than during baseline weeks without ADAS while such behavior was not observed in adult drivers . All adult drivers tended to keep longer headways when driving at night than during daytime to compensate for poor vision conditions but no such compensation behavior was observed in the teens . In addition teen and young adult drivers had more aggressive following behavior than middle aged and older drivers . One limitation of this study is that the findings of this study are only addressing the short term effect of ADAS exposure and future studies are needed to examine the longitudinal effect . The findings of this study suggest that the design of future ADAS should consider minimizing potential negative impacts on teen driver behavior . | The impact of an ADAS on age related differences in drivers following behavior on real roads were examined. Potential negative effects of ADAS on teen drivers following behavior were observedbut not for adult drivers. Factors affecting drivers following behavior were investigated by mixed model analyses. All adult drivers showed compensation behavior when driving at night but no such behavior was observed in the teens. ADAS can provide safety benefits to drivers and it may also bring unexpected negative consequences. |
S0001457520315918 | Pedestrian crossings are sites in which vehicles and pedestrians can crash into each other and are very important in terms of urban traffic . Drivers and pedestrians are more likely to violate traffic regulations and thus adversely affect traffic safety and flow in streets that have many such crossings . Careful planning of pedestrian crossing locations provides a solution to these problems . In this study a corridor based analysis of such sites is performed . Twenty four criteria that are considered to affect pedestrian crossing locations and traffic flow aredetermined . Based on these criteria the most suitable pedestrian crossing scenario is identified using Geographical Information Systems . The Analytic Hierarchy Process and VlseKriterijuska Optimizacija I Komoromisno Resenje from Multi Criteria Decision Analysis methods are used to evaluate the pedestrian crossing locations and PTV VISSIM is used to examine the impact of these sites on traffic . The proposed method is then applied to a case study of Erzurum Turkey that involves determining the best pedestrian crossing scenario . The results show that the most suitable scenario is S.2 . In terms of the evaluation criteria this alternative scenario provides an improvement of up to 50 over the current situation . Finally a sensitivity analysis is performed to reveal the effect of changing the criteria weights on the evaluation process . | The performance of pedestrian crossing locations is evaluated. A GIS and microsimulation based multi criteria decision analysis approach is applied. A hybrid AHP and VIKOR approach model is proposed. 11 geographic related and 13 traffic related criteria are considered. Results show that proposed scenarios are better than current situation. |
S000145752031592X | A hierarchical Bayesian peak over threshold approach is proposed for conflict based before after safety evaluation of Leading Pedestrian Intervals . The approach combines traffic conflicts of different sites and periods to develop a uniform generalized Pareto distribution model for the treatment effect estimation . The hierarchical structure has three levels a data level that consists of modeling the traffic conflict extremes through the POT approach a latent process level that relates GPD parameters of the data level to certain covariates and a prior level with prior distributions to characterize the latent process . The approach was applied to a before after safety evaluation of leading pedestrian interval in Vancouver BC . Pedestrian vehicle traffic conflicts were collected from treatment and control sites during the before and after periods using an automated computer vision analysis technique . The treatment effect was measured by the best fitted GPD model with the calculation of the odds ratio . The overall treatment effect varies from 18.1 20.9 in terms of reduction in the estimated extreme serious conflicts . The treatment effect indicates a considerable improvement in pedestrian safety after the implementation of the LPI and the consistent results demonstrate a reliable BA safety evaluation . As such the proposed approach is recommended as a promising tool for BA safety studies particularly in cases where collision data is limited . | A conflict based EVT before after safety study is used to evaluate treatment effect of LPI. A hierarchical Bayesian peak over threshold approach is proposed to model conflict extremes. A hierarchical Bayesian structure is used to incorporate covariates and unobserved heterogeneity. Traffic conflicts of different sites and periods are combined to evaluate the treatment effect. Significant safety improvements are found after the implementation of LPI. |
S0001457520315931 | Road accidents are one of the leading causes of death and injuries among adolescents and young adults . Road safety education programs aim to promote safe traffic behavior through information skills training or fear appeals . During the last decade an intervention type using victim testimonials has been developed . These types of programs aim to promote road safety by connecting a personal narrative of choices and consequences to the beliefs and behaviors of the audience . Studies on the effectiveness of this type of road safety programs among youngsters who are not yet drivers are still limited . | We examined the effect of a school based road safety educational program using testimonials for lower secondary school. Only a small effect on knowledge on risk factors in traffic was found. No effect was found on overall cycling behavior and seat belt use. Gender parental educational background and risky cycling behavior did not modify the effect on behavior. |
S0001457520315943 | Music can influence car following performance . However it is not well resolved about its mediation effect on car following when the drivers personalities are considered . We investigated how music style and tempo influence car following with different personalities . Twelve tracks were used in this study four for each music tempo range i.e . slow medium and fast tempo and six for each music style i.e . classical and pop one . The results showed introverts were more susceptible to music and tend to listen to slow tempo music and classical one . In addition pop music aroused the drivers more than classical and may induce closer headway distance . Furthermore with the tempo speeding up the drivers were more excited less concentrated and performed less stablely . The medium music tempo was the most appropriate choice for keeping stable headway distance and taking actions to the changes of the leading vehicle . The present study shows personality can mediate the influence of music listening while driving and music style and tempo can impact the mediation in a specific way . The study provides a guide on the music choice during driving and may bring benefits to the configuration of the music radio program and car music player . | Introverts are susceptible to music and prefer slow tempo and classical music. Pop music aroused more than classical one and induce closer headway time. Medium music tempo was most appropriate for keeping stable car following. Drivers were more excited and less concentrated with tempo speeding up. |
S0001457520315955 | Road crashes have become a leading cause of death in China . Although enormous efforts have been exerted to determine the factors that affect individual crash incidents neighborhood level crash incidence in Chinese cities has not been sufficiently analyzed . This study fills this gap by quantifying the effects of built environment factors on neighborhood level automobile involved crash density in urban China and identifying its mediators and mediating effects . In American suburbs urban sprawl is widely recognized to render neighborhoods unsafe for residence thus leading to a high crash incidence . This study compares the characteristics of built environments between inner city neighborhoods and the new neighborhoods that have been developed through Chinas state led suburbanization since 2008 to reveal how this suburbanization provides a safer neighborhood environment . A structural equation model is used to examine the relationships among suburbanization built environment factors and NACD in the city proper of Chengdu the largest metropolis in southwest China . Thus this study contributes new empirical evidence to the debates over urban designs that are safest for traffic . Moreover this study enriches our understanding of different sociospatial consequences between American style urban sprawl and Chinas state led suburbanization . | Chinas post 2008 suburbanization promotes traffic safety in the suburb. NACD tends to get lower with high mixed land use and high density expressway. In Chengdu City Proper the suburb tends to have lower crash density than inner city by 26.9 . |
S0001457520315967 | During highly automated driving drivers no longer physically control the vehicle but they might need to monitor the driving scene . This is true for SAE level 2 where monitoring the external environment is required it is also true for level 3 where drivers must react quickly and safely to a take over request . Without such monitoring even if only partial drivers are considered out of the loop and safety may be compromised . The OOTL phenomenon may be particularly important for long automated driving periods during which mind wandering can occur . This study scrutinized drivers visual behaviour for 18 min of highly automated driving . Intersections between gaze and 13 areas of interest were analysed considering both static and dynamic indicators . An estimation of self reported mind wandering based on gaze behaviour was performed using partial least squares regression models . The outputs of the PLS regressions allowed defining visual strategies associated with good monitoring of the driving scene . This information may enable online estimation of the OOTL phenomenon based on a drivers spontaneous visual behaviour . | In self driving cars mindwandering can make the driver out of the loop. The level of mindwandering was estimated by analysing gaze behavior. Partial least squares regression models were used to identify visual strategies. The best model used both static and dynamic visual indicators. The study may contribute to the design of driver monitoring systems. |
S0001457520315979 | Although numerous efforts have been devoted to exploring the effects of area wide factors on the frequency of pedestrian crashes in neighborhoods over the past two decades existing studies have largely failed to provide a full picture of the factors that contribute to the incidence of zonal pedestrian crashes due to the unavailability of reliable exposure data and use of less sound analytical methods . Based on a crowdsourced dataset in Hong Kong we first proposed a procedure to extract pedestrian trajectories from travel diary survey data . We then aggregated these data to 209 neighborhoods and developed a Bayesian spatially varying coefficients model to investigate the spatially non stationary relationships between the number of pedestrianmotor vehicle crashes and related risk factors . To dissect the role of pedestrian exposure the estimated coefficients of models with population walking trips walking time and walking distance as the measure of pedestrian exposure were presented and compared . Our results indicated substantial inconsistencies in the effects of several risk factors between the models of population and activity based exposure measures . The model using walking trips as the measure of pedestrian exposure had the best goodness of fit . We also provided new insights that in addition to the unstructured variability heterogeneity in the effects of explanatory variables on the frequency of PMV crashes could also arise from the spatially correlated effects . After adjusting for vehicle volume and pedestrian activity road density intersection density bus stop density and the number of parking lots were found to be positively associated with PMV crash frequency whereas the percentage of motorways and median monthly income had negative associations with the risk of PMV crashes . The use of population or population density as a surrogate for pedestrian exposure when modeling the frequency of zonal pedestrian crashes is expected to produce biased estimations and invalid inferences . Spatial heterogeneity should also not be negligible when modeling pedestrian crashes involving contiguous spatial units . | Using population as a surrogate of pedestrian exposure leads to biased estimates. Activity based exposure measures should be used when modeling pedestrian crashes. Travel diary survey offers a straightforward means to estimate pedestrian activity. Spatial heterogeneity is worthy of note in zonal pedestrian crash frequency models. |
S0001457520315992 | Given the severe traffic safety issue tremendous efforts have been devoted to identify the crash contributing factors for developing and implementing safety improvement countermeasures . According to the study findings driving behaviors have attributed to the majority crash occurrence among which inadequate driving capability is a key factor . Therefore a number of studies have been conducted for developing techniques associated with the driving capability assessment and its various improvement . However the conventional assessment approaches such as driving license exams and vehicle insurance quotes have only focused on basic driving skill evaluations or aggregated driving style classifications which failed to quantify driving capability from the safety perspective with respect to the complex driving scenarios . In this study a novel longitudinal driving capacity assessment and ranking approach was developed with naturalistic driving data . Two Responsibility Sensitive Safety based driving capability indicators from the perspectives of risk exposure and severity were first proposed . Then Bayesian Tobit quantile regression models were introduced to explore the relationships between driving capability indicators with trip level characteristics from the aspects of travel features operational conditions and roadway characteristics . The modeling results concluded that nighttime driving and higher average speed would lead to higher longitudinal collision risk and its severity . Besides the BTQR models have provided varying factors significances among different quantile levels for instance driving duration is only significant at high quantiles for the driving capability indicators implying that duration only affects drivers with large longitudinal risk exposures and strong close following tendencies . Furthermore the case studies provided how to deploy the developed model to obtain the relative longitudinal driving capability rankings . Finally the model applications from the aspects of commercial fleet safety management and comparing the autonomous vehicles longitudinal driving behaviors with human drivers have been discussed . | Proposed two Responsibility Sensitive Safety RSS based longitudinal driving capability indicators. Utilized Bayesian Tobit quantile regression BTQR models to quantify driving capability with trip level characteristics. Presented case studies for longitudinal driving capability assessment. Discussed model applications for fleet safety management and autonomous vehicle AV performance evaluations. |
S000145752031602X | This paper investigates factors associated with the severity of pedestrian outcomes from motor vehicle crashes by analyzing a database of all 13 856 reported pedestrian crashes in Colorado over an 11 year period from 2006 to 2016 . A total of 14 391 pedestrians were involved in these crashes resulting in 612 pedestrian fatalities 11 576 pedestrian injuries and 2203 property damage only outcomes . The objective is to analyze crash records as similarly compiled by other states to show how lives potentially saved by improved factor levels can be estimated as needed for benefit cost comparisons of alternative countermeasures . | 13 856 reported pedestrian vehicle crashes in Colorado from 2006 to 2016 were analyzed. 14 391 pedestrians were involved in these crashes causing 612 pedestrian fatalities and 11 576 pedestrian injuries. Significant factors were intersection proximity lighting vehicle type and speed ped age and impairment and driver impairment. Lives potentially saved by having better factor levels present are estimated using risk ratios from logistic regression. Lives saved estimates reflect relative magnitudes of benefits that might be achieved by potential countermeasures. |
S0001457520316031 | The blooming of intelligent connected vehicle has been continuously shaping a hybrid traffic environment in which the road is shared among ICVs and vehicles driven by human drivers . However due to the insufficient understanding of the human driving strategy and style the conflicts between ICVs and human drivers have arisen public attention threatening the road safety and bottlenecking the development of ICV . In order to embed the human driving strategy in the intelligent driving system researchers have been rolling out efforts on driver modeling . Most driver models however still suffer from the limited application scope or poor transparency . Within our finite horizons a unified and readable driver model for various driving scenarios is generally unobtainable . In this work we tried to model the human driving strategy from an aspect of human nature that is the way human drivers respond to the driving risk . We employed the risk field theory to model the environmental risk in a comprehensive manner . By studying the risk response strategy from the driving data of 24 human drivers we proposed a unified structure which we call the risk response driver model to model the human driving strategy . This model provides access to learning not only the average driving strategy of a group of human drivers but also the specific driving style of a single driver . The explicit and readable driving strategy produced by RRDM can be directly employed to reproduce human like longitudinal driving control . We verified the performance of our model in car following tasks and found that its human like driving performance is recoverable among the human drivers who participated in the tests . | a modified driving risk field model is developed for risk assessment in the car following scenario. a driving behavior modeling diagram is proposed by analyzing how drivers respond to driving risk. an intuitive car following model RRDM is proposed to explicitly reveal individualized driving style. an RRDM based exemplary application for human like longitudinal control is conducted in simulation. |
S0001457520316043 | As the use of cannabis for medical purposes becomes increasingly prevalent driving under the influence of cannabis is emerging as a major public health issue . Understanding current behaviours attitudes and perceptions around DUIC in medical cannabis users is an important first step in addressing this issue . Here we present the results from the driving related subsection of the Cannabis as Medicine 2018 2019 Survey of current Australian medical cannabis users . Of the 806 respondents who reported driving a motor vehicle in the last month 34.6 said they typically drive within 3 hours of cannabis use thereby risking DUIC while more than 50 waited at least 7 hours before driving . A majority of respondents thought that their medical cannabis use did not affect their driving ability and most denied any specific effects of cannabis on speeding risk taking reaction time attentiveness or lane departures . A substantial majority felt confident in accurately assessing their own driving ability after using medical cannabis . Binary logistic regression showed that frequency of use and confidence to assess driving ability were strongly related to DUIC behaviour . These results suggest a relatively high prevalence of DUIC and low perception of risk among this sample of medical cannabis users . Further research is needed to better understand the acute and chronic effects of medical cannabis use on driving and the relation between perceived and actual driving ability . | Some medical cannabis patients at risk of driving under the influence of cannabis. Most drivers disagree that cannabis impairs driving. Driving under the influence of cannabis perceived to be low risk. Majority of drivers wait at least 7 hours before driving. Likelihood of driving under the influence related to frequency of use |
S0001457520316055 | Road hazard perception is considered the most prominent higher order cognitive skill related to traffic accident involvement . Regional cultures and social rules that govern acceptable behavior may influence drivers interpretation of a traffic situation and consequently the correct identification of potentially hazardous situations . Here we aimed to compare hazard perception skills among four European countries that differ in their traffic culture policies to reduce traffic risks and fatal crashes Ukraine Italy Spain and Sweden . We developed a static hazard perception test in which driving scenes with different levels of braking affordance were presented while drivers gaze was recorded . The test required drivers to indicate the action they would undertake to brake vs. to keep driving . We assessed 218 young adult drivers . Multilevel models revealed that the scenes levels of braking affordance modulated drivers behavior . As the levels of braking affordance increased drivers responses became faster and their gaze entropy decreased . The country of origin influenced these effects . Ukrainian drivers were the fastest and Swedish drivers were the slowest to respond . For all countries the decrement in response times was less marked in the case of experienced drivers . Also Spanish drivers showed the most structured visual search strategy whereas the Italians had the most rigid one . These results suggest that road hazard perception can be defined cross culturally with cultural factors modulating response times and visual search strategies . Our results also support the idea that a multimodal assessment methodology is possible for mass testing of road hazard perception and its outcomes would be relevant to understand how different traffic cultures shape driving behavior . | We compared hazard perception among drivers from Ukraine Italy Spain and Sweden. Road hazard levels modulate response times and visual search strategies. There are cross cultural differences in road hazard perception. Cultural factors modulate the promptness of drivers responses. Cultural factors modulate drivers visual search strategies. |
S0001457520316067 | This study evaluated the impact of an optimal in vehicle advanced warning information service in a connected vehicle environment to prevent secondary crashes . Driving simulation experiments were designed and performed to analyze driving behavior . The forward crash situation was reproduced in a simulated highway environment and the safety effects were assessed based on simulation data from a driving simulator . To explore and analyze the effectiveness of crash notifications from the advanced warning information system for preventing secondary crashes this study utilized repeated measures of multivariate analysis of variance repeated measures of ANOVA paired t test and Wilcoxon signed rank test . The results from this paper indicate that a warning information system was effective to prevent secondary crash risks in general . | This study evaluated the safety effect of advanced warning information systems on secondary crash risk under connected vehicle environment. Drivers behaviors are analyzed according to the forward crash notifications on the road where the crash occurred. To explore the effectiveness of the system this study utilized repeated measures design. The results indicate that the warning information system can be effective to prevent secondary crash risks. |
S0001457520316080 | This driving simulator study compared drivers eye movements during a series of lane changes which required different levels of motor control for their execution . Participants completed 12 lane changing manoeuvres in three drives categorised by degree of manual engagement with the driving task Fully Manual Drive Manual Intervention Required Fully Automated Drive . For Partial automation drivers resumed control from the automated system and changed lane manually . For Full automation the automated system managed the lane change but participants initiated the manoeuvre by pulling the indicator lever . Results were compared to the Manual drive condition where drivers controlled the vehicle at all times . For each driving condition lane changing was initiated by drivers at their discretion in response to a slow moving lead vehicle which entered their lane . Failure to change lane did not result in a collision . To understand how different motor control requirements affected driver visual attention eye movements to the road centre and drivers vertical and horizontal gaze dispersion were compared during different stages of the lane change manoeuvre for the three drives . Results showed that drivers attention to the road centre was generally lower for drives with less motor control requirements especially when they were not engaged in the lane change process . However as drivers moved closer to the lead vehicle and prepared to change lane the pattern of eye movements to the road centre converged regardless of whether drivers were responsible for the manual control of the lane change . While there were no significant differences in horizontal gaze dispersion between the three drives vertical dispersion for the two levels of automation was quite different with higher dispersion during Partial automation which was due to a higher reliance on the HMI placed in the centre console . | Levels of automation were used to control the motor control requirements needed from drivers to perform the given task. Drivers have a more dispersed gaze with lesser motor control. However as they prepare for the lane change their gaze pattern tends to converge. Drivers gaze behaviour during an automated lane change is similar to the one described on previous literature for manual lane changes. Transitions of control made drivers look to the instrument cluster suggesting a need for system status information. |
S0001457520316092 | Guardrail end terminals are designed to gradually decelerate vehicles during impact and protect vehicle occupants from severe injuries . It has been observed that some in service end terminals are damaged and it is unclear if their safety performance is still acceptable . The objectives of this study were to examine the conditions of in service end terminals and to evaluate the performance of damaged relative to undamaged end terminals in simulated impacts . Common damage patterns of guardrail end terminals were investigated by using post crash pictures collected from the National Automotive Sampling System Crashworthiness Data System . Conditions of in service end terminals mounted along roads in portions of six U.S. states were examined by using a sample from the second Strategic Highway Research Program Roadway Information Database . Finite Element models of two minorly and three severely damaged ET Plus systems a commonly used energy absorbing guardrail end terminal along U.S. roads were developed . To evaluate the performance of the damaged ET Plus systems we performed impact simulations with vehicle to damaged ET Plus models according to the National Cooperative Highway Research Program 350 test conditions 330 . Of the 1000 in service end terminal cases we investigated 73 were undamaged 18 had minor damage and 8 had major damage . Increases in the average vehicle deceleration rates maximum vehicle yaw angles and vehicle local deformations were observed in simulated impacts with damaged ET Plus end terminals relative to impacts with undamaged ET Plus end terminals . For one damaged ET Plus a secondary collision was observed . Overall we found that the damaged end terminals usually increased collision severity when compared with undamaged end terminals . The findings of this study point out the need for in service performance evaluations and proper maintenance and repair practices of end terminals . The simulation models developed in this study could be further employed to investigate device performance in crash situations that are physically impractical to test and investigate the effects of site characteristics on device performance . The simulation models could also supplement crash tests to certify new hardware designs . | Common damage patterns of guardrail end terminals were investigated by using post crash pictures collected from the NASS CDS. Finite Element FE models of two minorly and three severely damaged ET Plus systems were developed. Increasing avg. deceleration max yaw angles and deformations were observed in the vehicle models impacting damaged ET Plus. It pointed out the need for in service performance evaluations and proper maintenance and repair practices of end terminals. |
S0001457520316110 | As of 2022 lane keeping assistance systems and other selected safety technologies will become mandatory in new European vehicles to increase safety for passengers pedestrians and cyclists . Lane support systems are based on advanced computer vision technologies and they are expected to give safety benefits in reducing Ran of Road and head on crashes comparable to already consolidated physical countermeasures like rumble strips . Anyway despite the assumed technology readiness there is still much uncertainty regarding the needs of vision systems for reading the road and limited results are still available from in field testing . In such framework the paper presents an experimental test of LSS performance carried out in two lane rural roads with different geometric alignments and sections characterized by variable maintenance conditions for pavement and markings . LSS faults were detected in 2.6 of the sections running the roads in day light and dry pavement conditions . Logit models were developed to better understand road characteristics and conditions that can affect the system performance . The Firth penalized maximum likelihood method was applied to estimate the logistic regression coefficients and standard errors to account for the rareness of the events . Results show that luminance coefficient of marking in diffuse lighting conditions and horizontal curvature radius are the main predictors of system fault . Based on the case study and test conditions other marking characteristics longitudinal cracking verge width and running speed resulted not significant in explaining the probability of fault . Thresholds values for Qd and 1 R are suggested and remarks on road maintenance and design standards presented . | Provided a comprehensive road safety framework for Lane Support System LSS . Conducted a systematic collection of data on LSS operation and road characteristics. Identified the most suitable statistical approach for logit regression of rare events. Identified significant road factors affecting the LSS performance in day and dry conditions. Identified the critical research needs within the field of Operational Design Domain for LSS. |
S0001457520316122 | Attributions of the causes of accidents to human error are problematically reductive yet such attributions persist in media coverage . Few experiments have examined how human error attributions affect peoples perceptions . An experiment compared attributions of accidents to human error versus other causes . Participants | We manipulated attributions of accidents human error versus other causes in 50 real news stories. Human error attributions resulted in greater endorsement of individual punishment. Human error attributions resulted in less perceived organizational responsibility. Human error attributions were perceived as more preventable retrospectively. The pattern of results replicated in a second experiment. |
S0001457520316134 | Left turns are some of the most dangerous maneuvers drivers face as they involve a complex decision making process . Indeed drivers must wait for an adequate gap in oncoming traffic to safely complete a left turn maneuver . In this context incorrectly assessed gaps can lead to severe crashes and severe traffic delays at intersections . This study tests the potential of Augmented Reality technology built into connected vehicle technology to improve the safety of left turn maneuvers of connected vehicles by adding visual virtual information to the driver . To achieve this goal a driving simulator study was carried out . The effectiveness of the system was tested and the ability of young drivers to detect adequate gaps between vehicles in the opposite lane to safely turn left was assessed with and without AR warnings at a two way stop controlled intersection under a connected vehicles environment . In the scenario projected on the simulation screen three different virtual warnings were displayed and tested a green red traffic light which informs the driver of the availability of an appropriate gap between opposing vehicles a traffic light with a timer showing the number of seconds available to safely perform the left turn maneuver a traffic light with an additionally activated audio warning system . Significant positive effects of AR warnings on driving performance and traffic safety were observed the number of safe left turns increased and the delays at the intersection decreased . In addition AR signaling improved driving behavior both during the waiting time with many more drivers waiting for the gap in front of the stop line to avoid disrupting oncoming traffic and turning movement reducing the average time it took to complete the left turn maneuver . This study confirmed the great potential of AR and connected vehicle technologies to improve general safety conditions on the road network especially under risky situations and difficult maneuvers . | Crash data show that left turns are quite dangerous maneuvers. Augmented Reality AR could enable future systems to detect dangers earlier. AR warnings increase the number of safe left turns of connected vehicles. Delays at intersection decreases using AR warnings. No significant differences are observed among different AR warning configurations. |
S0001457520316146 | The present paper discusses two fuzzy Surrogate Safety Metrics for rear end collision the Proactive Fuzzy SSM and Critical Fuzzy SSM . The objective is to investigate their applicability for evaluating the real time rear end risk of collision of vehicles to support the operations of advanced driver assistance and automated vehicle functionalities . The proposed Fuzzy SSMs are evaluated and compared to other traditional metrics on the basis of empirical observations . To achieve this goal an experimental campaign was organized in the AstaZero proving ground in Sweden . The campaign consisted of two main parts a car following experiment with five vehicles solely driven by Adaptive Cruise Control systems and a safety critical experiment testing the response of the Autonomous Emergency Braking system to avoid collisions on a static target . The proposed PFS is compared with the safe distance defined by the well known Responsibility Sensitive Safety model showing that it can produce meaningful results in assessing safety conditions also without the use of crisp safety thresholds . The CFS outperformed the well known Time To Collision SSM in the a priori identification of the cases where the tested vehicles were not able to avoid the collision with the static target . Moreover results show that CFS at the time of the first deceleration is correlated with the velocity of the vehicle at the time of collisions with the target . | Two Fuzzy Surrogate Safety Metrics FSSMs for rear end collision are presented. Unsafe situations are distinguished between critically and proactively unsafe. The new metrics are assessed based on test track experiments. FSSMs outperform traditional metrics based on crisps thresholds. FSSMs are suitable for supporting driving assistance and automation systems. |
S0001457520316158 | Run off the road crashes account for a significant proportion of severe injuries to vehicle occupants . Traffic barriers have been installed with an objective to keep vehicles on the roadway and prevent them from hitting natural obstacles like trees or boulders . However still injuries and fatalities of barrier crashes account for high proportion of fatalities on roadway . Due to challenging geometrics characteristics of Wyomings roadway a high mileage of barriers has been installed in the state . The high mileages of barriers result in a high number of barrier crashes in terms of crash frequency and severity due to high exposure . Previous studies mainly focused on crash frequency or individual crash severity . However it has been recognized the importance of accounting for both aspects of crash severity and crash frequency . So in this study crashes are aggregated across different barriers and those crashes were converted into costs by considering the impacts of both crash severity and frequency . However one of the main challenges of this type of dataset is highly skewness of crash data due to its sparseness nature . An improper use of model distribution of crash cost would result in biased estimations of the covariates and erroneous results . Thus in order to address this issue a semi parametric method of quantile regression technique was implemented to account for the skewness of the response by relaxing model distribution parameters . Also to account for the heterogeneity in the dataset due to barriers types a random intercept model accounting for the structure of the data was implemented . In addition interaction terms between significant predictors were considered . Understanding what factors with which magnitude contribute to the barrier crash costs is crucial for the future barriers optimization process . Thus contributory factors to barriers crash cost with high medium and low values corresponding to 95 | In this study crashes are aggregated across different barriers and those crashes were converted into costs by considering both impacts of crash severity and frequency. A semi parametric method of quantile regression technique was implemented to account for the skewness of the response by relaxing model distribution parameters. To account for the heterogeneity in the data set a random intercept model accounting for the structure of the data was implemented. Contributory factors to barriers crash cost with low medium and high values corresponding to 95. 70. and 60. percentiles were considered. The implemented model was compared with standard linear quantile model indicting that linear quantile mix model enhance the model performance significantly. |
S0001457520316183 | The threat assessment process is a crucial part of intelligent vehicles for evaluating the levels of criticality and taking possible measures to avoid the collision especially for the collision avoidance systems . In this study a novel threat assessment framework based on the drivers evasive behavior namely the CPIC is proposed which integrates the crash probability and inevitable crash state to be widely used by different CAS in different scenarios . In the first step of the CPIC framework the detailed evasive driver behavior models in the form of probability density functions were introduced to generate more realistic collision avoidance trajectories . Two techniques for sampling these trajectories namely the Markov Chain Monte Carlo and adaptive Gaussian mixture framework methods were utilized to ensure the samples were from the area of high probability density in the E DBMs . The CP value could be derived by considering multiple collision avoidance trajectories . To confirm the IC state in step 2 the CPIC framework employed the driving limit based approach for IC checking which combined the CP value to double check the unavoidable collision . A total of 82 critical events from the real world naturalistic driving study the Strategic Highway Research Program 2 were extracted to verify the performance of the CPIC framework in different scenarios . Results show that the proposed method clearly revealed the risk levels when two vehicles were approaching and 80 events were successfully identified as near crashes crashes . Moreover the real time performance of the CPIC framework was also demonstrated . The findings indicate this CPIC framework could be used in practical applications of IVs in different scenarios . | A comprehensive threat assessment framework combining crash probability and inevitable crash state is proposed. Detailed evasive driver behavior models are introduced to the proposed framework. The framework can be used for both warning based and intervention based collision avoidance systems in different scenarios. The prediction performance of the proposed framework is demonstrated by 82 real world critical events in the SHRP2 program. The ability of real time computation for the proposed framework is verified. |
S0001457520316195 | Pedestrian protection is an important component of road safety . Intersections are dangerous locations for pedestrians with mixed traffic . This paper aims to predict potential traffic conflicts between pedestrians and vehicles at signalized intersections . Using detection and tracking techniques in computer vision pedestrians and vehicles features are extracted from video data . An LSTM neural network is proposed to predict the pedestrian vehicle conflicts 2 s ahead . The established model reaches an accuracy of 88.5 at one signalized intersection . It is further tested at a new intersection reaching the accuracy of 84.9 while the new data merely takes up 30 of the training data set . This indicates that the proposed model is promising to be implemented at different locations . Moreover the proposed model can also be applied to develop collision warning systems under the Connected Vehicles environment . | Trajectories of pedestrians and vehicles are generated using automated video techniques. The LSTM model is established to predict potential pedestrian vehicle conflicts at the signalized intersections. The external testing results show the model generalizes well at different locations. The proposed model can be applied in collision warning systems under the Connected Vehicles environment. |
S0001457520316213 | Connected Vehicles technology has been used to address safety issues on highway horizontal curves . Existing curve warning systems are either using curve warning signs or providing drivers with an in vehicle curve warning message in advance allowing drivers to adjust their speed prior to the vehicle entering the curve . In practice drivers might be compliant before entering the curve but may pick up the speed in the curve . Therefore it remains a problem that existing curve warning systems are not able to guide drivers by providing necessary speed warnings through the entire course of approaching entering navigating and leaving horizontal curves . Therefore the objective of this study is to improve curve speed compliance by proposing a guidance oriented Advanced Curve Speed Warning system with a focus on providing guided curve speed messages throughout the horizontal curves . The Advanced CSW system is based on Dedicated Short Range Communication enabling vehicle infrastructure communication . Anytime the vehicle is speeding the guided message will be displayed until the vehicles speed is within compliant range . Drivers who use the Advanced CSW can receive multiple guided messages from the in vehicle heads up display through the entire course of navigating through horizontal curves . Thirty participants are recruited to perform the driving experiment on the simulator of driving through a series of horizontal curves under various geometric roadway and traffic conditions . These conditions include different curve severity illumination and pavement wetness levels . The Advanced CSW systems performance was evaluated in terms of the speed difference which measures the gap between the in curve mean speed and curve advisory speed . The results were compared with the performance of speed difference by driving with CSW or CSO through the entire curve . The experiment data was modeled using the mixed linear model with random effects which includes the individuals driving behavior . In summary when male drivers navigate through the horizontal curves under different curve speed warning systems their speed compliance is significantly increased with continuous and guided messages provided in comparison with the speed compliance under the one time curve speed warning message and the curve sign only . Female drivers improve their speed compliance in the curve by using curve signs only comparing to using one time curve speed warning message or continuous guided curve speed warning messages . Also male drivers speed differences by using the guided system are significantly reduced by 6.537.68 mi h compared to driving with curve signs only or one time curve speed warning message . In addition there is also a speed reduction of 1.81 mi h if male drivers receiving continuous guided messages in the curve during the daytime than during the nighttime . The proposed adaptive system based on that is adaptive to the vehicles real time speed and location by providing a new direction in designing effective curve warning systems . The speed guided messages through the entire course of approaching entering navigating and leaving horizontal curves can solve the current issue of speed incompliance by using the existing curve warning systems . | Propose an advanced curve speed warning system A CSW to address the in curve speed incompliance issue due to one time warning nature. A CSW provides guided speed warning through driving the entire course of horizontal curves via CV enabled DSRC based V2I commutation. A mixed linear model with random effects is developed to capture individuals driving behavior. A CSW is adaptive to the vehicles real time speed and location updating curve advisory speed if pavement friction is changed. A CSW significantly enhances male drivers speed compliance when compared to the existing CV based curve warning system. |
S0001457520316249 | In SAE Level 3 automated driving taking over control from automation raises significant safety concerns because drivers out of the vehicle control loop have difficulty negotiating takeover transitions . Existing studies on takeover transitions have focused on drivers behavioral responses to takeover requests . As a complement this exploratory study aimed to examine drivers psychophysiological responses to TORs as a result of varying non driving related tasks traffic density and TOR lead time . A total number of 102 drivers were recruited and each of them experienced 8 takeover events in a high fidelity fixed base driving simulator . Drivers gaze behaviors heart rate activities galvanic skin responses and facial expressions were recorded and analyzed during two stages . First during the automated driving stage we found that drivers had lower heart rate variability narrower horizontal gaze dispersion and shorter eyes on road time when they had a high level of cognitive load relative to a low level of cognitive load . Second during the takeover transition stage 4 s lead time led to inhibited blink numbers and larger maximum and mean GSR phasic activation compared to 7 s lead time whilst heavy traffic density resulted in increased HR acceleration patterns than light traffic density . Our results showed that psychophysiological measures can indicate specific internal states of drivers including their workload emotions attention and situation awareness in a continuous non invasive and real time manner . The findings provide additional support for the value of using psychophysiological measures in automated driving and for future applications in driver monitoring systems and adaptive alert systems . | Drivers have systematic psychophysiological patterns in automated driving. Psychophysiological patterns are good indicators of takeover requests. Internal states can be specified by psychophysiological data in takeover transitions continuously. The findings are helpful for driver monitoring and adaptive alert systems design in automated driving. |
S0001457520316250 | Benefiting from the rapid development of communication and intelligent vehicle technology in recent years most traffic information is capable of being collected processed and transmitted to each vehicle through a connected and automated vehicles system . To meet the higher requirements of driving safety in CAVs environment it is necessary to develop more effective safety evaluation indicators that combine all the traffic information received by the vehicle . To this end this study proposes a novel methodology for risk perception and warning strategy based on safety potential field model to minimize driving risk in the CAVs environment . A dynamic safety potential field model was constructed to describe the spatial distribution of driving risk encountered by vehicles . This safety potential field model can comprehensively consider the impact of various types of traffic information on driving risk . And then a novel driving risk indicator named potential field indicator | The acceleration and the steering angle are incorporated into potential field model for the first time. The model is capable of showing the dynamic spatial distribution of the safe potential field under different motion conditions. A novel risk indicator was proposed based on the safe potential field. A warning strategy is proposed for preventing accidents. |
S0001457520316262 | A pre and post survey of psychosocial variables was used to examine the effect of a compulsory pre licence driver education program for drivers aged 1620 years in the Australian Capital Territory . While the final survey was collected by telephone all other surveys were completed online . Two way mixed ANOVAs revealed that sensation seeking and optimism bias increased over time while illusionary invulnerability and differential association fell . Participants perceived driving as more risky 912 months after completing the course compared to their views prior to the course . These results suggest that the program may have a limited effect on these five psychosocial factors over time . Policy makers may need to carefully consider the reasons for providing driver education the optimal time during the licensing process to provide this education and the financial and social costs of doing so . | Pre licence driver education is mandatory for new drivers in the Australian Capital Territory. Young novice driver sensation seeking and optimism bias increased between pre and 912 months post the education course. Illusionary invulnerability and differential association decreased over this period. Results indicate that the program has only limited effect on psychosocial factors. |
S0001457520316274 | Traffic accidents are a global concern due to the elevated mortality rates of both drivers and pedestrians . The World Health Organization declared 2011 2020 as the Decade of Action for Road Safety endorsing initiatives to reduce traffic related deaths . Yet despite these incentives fatal accidents still occur . Different studies have linked deficits in executive functions to risky driving attitudes and crashes . The present study focuses on demographic cognitive and personality factors related to the prefrontal cortex that are characteristic of drivers prone to risky behavior behind the wheel . The penalty Points System was used to classify drivers as safe with no point loss over a two year period or risky with full point loss during the same interval . A neuropsychological assessment of prefrontal cognitive functions was carried out on each group to identify variables associated with safe and risky behavior . Neuropsychological indexes were obtained from a continuous performance task without cue a continuous performance task with cue the Tower of Hanoi test and the Neurologically related Changes in Personality Inventory . A Discriminant Analysis found that education level reaction times in Simple and Conditioned Attention learning errors in the Tower of Hanoi and vulnerability in the personality test best predicted whether drivers were likely to be in the safe or risky group . Finally a cross validation analysis performed on the same sample correctly classified 87.5 of the drivers . These data suggest that prefrontal dysfunction contributes to risky behavior behind the wheel . The inclusion of cognitive programs to identify and train drivers with this propensity could reduce risky driving and consequently save lives on the road . | An online neuropsychological evaluation discriminates between offender non offender drivers. Demographic cognitive and personality factors can define risky driver profiles. The vulnerability factor is higher in safe drivers than in repeat offenders. Education Level is the factor with the highest discriminative power. |
S0001457520316419 | This study applies a simulation based traffic conflict technique to evaluate the hypothesis that sun glare under upper vents exerts negative impacts on traffic safety in urban tunnels . A modified cellular automata model is applied to simulate the deceleration behavior due to sun glare in real traffic . And the model is calibrated and validated against the empirical data . Conict occurrences are generated through simulating vehicular interactions based on this model . Simulation experiments are conducted with different density and illuminance to evaluate the safety impacts of sun glare . Comparison of simulated conict occurrences shows that rear end conflicts occur more frequently as illuminance and density get higher . And the impacts of sun glare are more obvious on weak conflicts in moderate density flow and more severe conflicts in high density flows respectively . To alleviate the negative impacts of sun glare a sunshade system is designed based on the quantitative results . | A modified CA model for urban tunnel is proposed and validated. The safety impact of sun glare in urban tunnel is studied. A conceptualized sunshade system is designed to improve safety conditions in urban tunnel. |
S0001457520316420 | Car driving performance is negatively affected by the intake of alcohol tranquillizers sedatives and sleep deprivation . Although several studies have shown that the standard deviation of the lateral position on the road is sensitive to drug induced changes in simulated and real driving performance tests this parameter alone might not fully assess and quantify deviant or unsafe driving . Using machine learning we investigated if including multiple simulator derived parameters rather than the SDLP alone would provide a more accurate assessment of the effect of substances affecting driving performance . We specifically analysed the effects of alcohol and alprazolam . The data used in the present study were collected during a previous study on driving effects of alcohol and alprazolam in 24 healthy subjects . Various driving features such as speed and steering variations were quantified and the influence of administration of alcohol or alprazolam was assessed to assist in designing a predictive model for abnormal driving behaviour . Adding additional features besides the SDLP increased the model performance for prediction of drug induced abnormal driving behaviour . Driving behaviour influenced by alcohol and alprazolam was characterised by different feature importance indicating that the two interventions influenced driving behaviour in a different way . Machine learning using multiple driving features in addition to the state of the art SDLP improves the assessment of drug induced abnormal driving behaviour . The created models may facilitate quantitative description of abnormal driving behaviour in the development and application of psychopharmacological medicines . Our models require further validation using similar and unknown interventions . | Machine learning using multiple driving features improves the assessment of drug induced abnormal driving behaviour. Alcohol and alprazolam influenced driving behaviour in a different way. The created models may facilitate quantitative description of abnormal driving behaviour |
S0001457520316511 | This study introduces a method that allows the generation and safety evaluation of a scenario catalog derived from potential car pedestrian conflict situations . It is based on open source software components and uses the road layout standard OpenDRIVE to derive participants motion profiles with the support of available accident data . The method was implemented upon the open source framework openPASS and can simulate results for different active safety system setups and facilitates the prediction of system capabilities to decrease the relative impact velocities and collision configurations such as the point of impact . A demonstration case was performed where the scenario catalog was derived and used to evaluate pedestrian collisions with and without a generic autonomous emergency braking system . The AEB system aims to intervene in the event of an impending collision and might affect the outcome of a baseline scenario . The study indicated a change in the collision configuration and identified conflict situations less affected by the system . A particularly interesting finding was that some scenarios even led to a higher number of collisions for the AEB intervention in comparison to the baseline cases . | Automatic generation of potential accident scenarios between pedestrian and cars based on road layout descriptions. Introduction of an enhanced open source framework for simulation and evaluation of pedestrian car accident scenarios with open standards. Systematic evaluation of the effect of a generic AEB system on 100 000 scenarios generated from one road layout. |
S0001457520316535 | In recent years globally quantile based model and spatially conditional mean models have been widely and commonly employed in macro level safety analysis . The former ones assume that the model coefficients are fixed over space while the latter ones only represent the entire distribution of variable effects by a single concentrated trend . However the influence of crash related factors on the distribution of crash frequency is observed to vary over space and across different quantiles . Therefore a geographically weighted Poisson quantile regression model is employed to investigate the spatial heterogeneity of variable effects crossing different quantiles . Five categories including exposure socio economic transportation network and land use were selected to estimate the spatial effects on crash frequency . In the case study vehicle related crashes collected in New York City were used to validate the predicted performance of the proposed models . The results show that the GWPQR outperforms the NB QR and GWNBR for modeling the skewed distribution reconstructing the crash distribution and capturing the unobserved spatial heterogeneity . Additionally the significant coefficients are further used to classify all 21 variables into key important and general parts . Then we discuss how these factors affects the regional crashes over space and distribution of crash frequency . This study confirms that the influencing factors have varying effects on different quantiles of distribution and on different regions which could be helpful to provide support for making safety countermeasures and policies at urban regional level . | GWPQR model is applied to analyze the heterogeneity of crashes. Exposure traffic network socioeconomic and land use are considered in model. Accidents data collected in New York City are used to validate the fitting performance. The key variables are identified according to the significant coefficients. Spatially heterogeneous effects of key variables under different quantiles are analyzed. |
S0001457520316547 | There has been no scarcity in the literature of suggested antecedents of employee safety behavior and this paper brings together the disaggregated antecedents of safety behavior in the construction field . In total 101 eligible empirical articles are obtained . Bibliometric and context analyses are combined to identify the influential journals scholars keywords use of theory research methods and countries or regions of the empirical samples . The 83 factors that are identified are divided into five groups namely individual characteristics workgroup interactions work and workplace design project management and organization and family industry and society . This indicates that the causes of safety behavior are manifold . Various factors from different systems likely work in concert to create situations in which an individual chooses to comply with safety rules and participate voluntarily in safety activities . Given this we propose that safety behavior is only an ostensible symptom of more complex The SelfWorkHomeIndustry Society systems and establish a safety behavior antecedent analysis and classification model . Based on this model we develop a resource flow model illustrating why how and when the flow of resources between the five systemsnamely the self system work system home system workhome interface system and industry society systemeither promotes or inhibits safety behavior . The safety behavior antecedent analysis and classification model and resource flow model are based mainly on bioecological system theory and resources theories . Avenues for future theoretical development and method designs are suggested based on the reviewed findings and the two conceptual models . The intention with this systematic review together with the two integrated conceptual models is to advance theoretical thinking on how safety behavior can be promoted or instead inhibited . | A review of the research on antecedents of safety behavior in construction. From 101 empirical articles eighty three factors in five groups are identified. Propose a safety behavior antecedent analysis and classification model. Propose a safety behavior resource flow model. Bibliometric analysis and content analysis are used. |
S0001457520316560 | Norwegian authorities encourage people to commute by bicycle to improve public health decrease rush hour traffic jams and reduce pollution . However increasing the number of bicyclists especially in the rush hour traffic may increase the number of serious bicycle injuries . To explore trends in hospitalized bicycle injuries at a Norwegian level I trauma centre during the last decade . Data was extracted from the prospectively registered institutional trauma registry . We identified patients admitted after bicycle injuries between 2005 and 2016 . A total of 1543 patients were identified . Median age was 40 years and 73 were males . The majority of weekday injuries occurred in the morning and during the afternoon rush hour peaking at 8 am . and 4 pm . The annual number of admitted bicycle injuries increased from 79 to 184 during the study period . Also an increase in the share of bicyclists using helmets was observed . The median Injury Severity Score of 10 remained unchanged . 63 had serious trauma while 34 suffered severe trauma . The absolute number of both serious and severe trauma increased annually . 36 had head and neck injuries while 16 had chest injuries graded with Abbreviated Injury Scale 3 . Loss of consciousness with Glasgow Coma Scale score 9 was seen in 7 . Median length of hospitalization was 3 days and 39 had surgery in one or more body regions . The 30 day mortality was 2.3 . The number of admitted bicycle injuries to our trauma centre is increasing . Rush hour injuries dominate during weekdays . Bicycle injuries can be devastating and deserve more public attention to promote road safety . | The number of admitted bicyclists to Oslo University Hospital increased 2.5 times from 2005 to 2016. The most common mechanism of injury were single bicycle crashes which made up two thirds of all injuries. The age distribution showed two peaks one for in the early teens and one for adults starting at 20 years and tapering off towards 70 years of age. Most bicycle injuries occurred during week day rush hours. An increasing trend in the use of helmets was observed during the study period despite no federal legislation. |
S0001457520316572 | Modern day Connected and Autonomous Vehicles with more than 100 million code lines running up to a hundred Electronic Control Units will create and exchange digital information with other vehicles and intelligent transport networks . Consequently ubiquitous internal and external communication within all CAV related nodes is inevitably the gatekeeper for the smooth operation . Therefore it is a primary vulnerable area for cyber attacks that entails stringent and efficient measures in the form of cybersecurity . There is a lack of systematic and comprehensive review of the literature on cyber attacks on the CAVs respective mitigation strategies anticipated readiness and research directions for the future . | Critical areas identified for Connected Autonomous Vehicles CAVs in combating cyber attacks. Integrated CAVs communication framework is developed for potential cyber attacks. Consolidated details of the cyber attacks on the CAVs in the Intelligent Transport System are presented. Mitigation strategies for CAVs cyber attacks along with future directions are discussed. |
S0001457520316584 | Selecting an appropriate exposure measure and functional form for Safety Performance Functions is critical in precisely predicting crash counts by different crash types for intersections . This study proposes a new approach namely Generalized Negative Binomial P model to model the complex relationship between crashes and different exposure measures by crash type for intersections which helps not only identify the most reliable exposure measure for intersection SPFs but also explore the most appropriate functional form of the NB models . To this end three types of SPF functional forms namely Power function Hoerl function 1 and Hoerl function 2 with different exposure measures including major road AADT minor road AADT and total AADT were estimated by crash type for stop controlled and two types of signalized intersections . The over dispersion of the SPF models was estimated using the exposure measures to account for crash data variation across different intersections . | Exposure measures and functional forms are investigated in intersections SPFs. Generalized Negative Binomial P models are estimated for intersection crash prediction. Overdispersion is parameterized to account for data heterogeneity. Exposure measures and functional forms vary across intersection types and crash types. |
S0001457520316596 | To support the coordination of road users in situations like merging or turning left an advanced driver assistance system for cooperative driving could be helpful whether driving manually or automated . This simulator study investigated the behavior of drivers being confronted with system failures . In two test situations with system failures the system could not complete the coordination properly and the driver was informed about the system failure and the abortion of maneuver coordination . The focus of this study was to analyze the effect of system failures on drivers trust in the system and whether an explanatory message provided by the system would increase acceptance . Therefore subjective data as well as gaze and physiological data of 32 participants were analyzed . The results revealed decreased trust in the system after experiencing a system failure but no long term effect was found . The drivers evaluated the timing as well as the content of the explanatory message as appropriate . The explanations were perceived as helpful but no effect on acceptance was found . | System failures during maneuver coordination are evaluated. The effect of an explanation of the system failure is investigated. The results revealed decreased trust in the system after a failure for short time. The explanations were perceived as helpful but no effect on acceptance was found. |
S0001457520316602 | Rural highways are an important component of highway networks in developing countries . The high fatality rates of single vehicle crashes in these highways recently attracted increasing attention . Given that most studies on the factors that affect the severity of single vehicle crashes in rural highways were conducted in developing countries the present study investigated this issue in a Chinese setting by analyzing the single vehicle crash data of rural highways in Anhui Province China from 2014 to 2017 . First in consideration of the unobserved heterogeneity of crash data a method that combines latent class analysis and binary logistic regression which is called LC BLR was applied to identify the significant factors that affect the severity of single vehicle crashes in rural highways . Second the goodness of fit and prediction accuracy of the LC BLR model and the BLR model were compared . Results revealed that the performance of the former was more satisfactory than that of the latter . Finally countermeasures were proposed based on the analysis of the main factors that affect each sub class crash in the LC BLR model . The LC BLR model results indicated that collision typewas significant in all three sub class models considered in the analysis but the effects on crash severity varied . Several variables demonstrated a significant effect in a specific sub class model thereby indicating that these factors were only effective in mitigating the crash severity of one sub class . The findings of this study can facilitate the development of cost effective policies or countermeasures for reducing the severity of single vehicle crashes in rural highways . | LCA and BLR were employed to identify factors affecting rural highway single vehicle fatal crashes in China. Driver age collision type and presence of a curve are significant in all three sub class models. Twelve factors only have a significant effect in specific sub class model. Road traffic safety management strategies and policies have been proposed in the context of developing countries. |
S0001457520316614 | The crash severity levels of two parties involved in a two vehicle accident may differ markedly and may be correlated . Separately estimating the severity levels of two parties ignoring their potential correlation may lead to biased estimation however modelling their severity levels simultaneously by using a bivariate modelling approach requires a complex model setting . Thus this study used generalized estimating equations to accommodate potential correlations when estimating the crash severity levels of two parties . To investigate the performance of the GEE models a case study on a total of 2493 crashes at 214 signalized intersections in Taipei City in 2013 is conducted . Univariate ordered probit model bivariate ordered probit model and GEE ordered probit model with different working matrices are respectively estimated and compared . The estimation results of GEE models showed that the GEE OP with the exchangeable working matrix performs best and the most influential factor contributing to crash severity is vehicle type followed by speeding angle impact and alcoholic use . Thus to curtail motorcycle usage by increasing parking fee or reducing parking space of motorcycles to crack down on speeding and alcoholic use and to redesign the signal timings to avoid possible angle impact accidents are identified as key countermeasures . | Crash severity levels of both parties in two vehicle accidents are modeled. The generalized estimating equations method is used to estimate ordered probit models. Comparisons with univariate and bivariate models in a detailed prediction performance matrix were conducted. Key risk factors are identified and corresponding countermeasures are proposed. |
S000145752031664X | Pedestrian safety plays an important role in the transportation system . Intersections are dangerous locations for pedestrians with mixed traffic . This paper aims to predict the near accident events between pedestrians and vehicles at signalized intersections using PET and TTC . With automated computer vision techniques mobility features of pedestrians and vehicles are generated . Extreme Value Theory is used to model PET and minimum TTC values to select the most appropriate threshold values to label pedestrians near accident events . A Gated Recurrent Unit neural network is further used to predict these events . The established model reaches an AUC value of 0.865 on the test data set . Moreover the proposed model can also be applied to develop collision warning systems under the Connected Vehicle environment . | Automated computer vision techniques are used to generate trajectories of pedestrians and vehicles from video data. Two Surrogate Safety Measures SSMs indicators are used to label the pedestrians near accident events. Extreme Value Theory EVT is used to select the most appropriate threshold values for SSMs indicators. A Gated Recurrent Unit GRU is used to predict the pedestrians near accident events. |
S0001457520316651 | Cell phone use while driving is becoming a key problem in traffic safety as it causes visual manual distraction and has been linked to increases in crash rates . The use of hand held phones has been banned in several countries yet research comparing the safety of hands free phone use with hand held has produced inconsistent results . Analysis of specific phone use characteristics could help move this traffic safety problem toward a solution but few studies have considered the influence on driving performance of specific sets of phone use characteristics in combination with other factors such as driving context and driver demographic characteristics . The main objective of this paper is therefore to identify and analyze these factors to determine their effects on driving performance indicators such as speed changes . To this end 1244 phone events were collected from 52 drivers from the Shanghai Naturalistic Driving Study the first naturalistic driving data in China . Because subtasks within a phone event may cause different visual manual distractions a hierarchical coding structure for phone events was built . A total of 5662 eyes off road cases and 4237 subtasks were extracted . The results showed that on average the participating drivers used the phone for 6.08 of their driving time for 17 of phone use time drivers used both hands to manipulate the phone and their average EOR time was 3.16 s which is equivalent to driving blindly for 22.82 m at an average speed of 7.22 m s or 26 km hr . The effect of phone use on driving performance including speed headway and lane offset was analyzed with ANOVA . Results showed that standard deviations of all three parameters were significantly lower during phone periods than during baseline periods . The speed SD during phone use was 0.95 lower than baseline the headway SD was 2.48 lower and the absolute lane offset SD was 685.72 lower than baseline . These lower SDs indicate that drivers operated their vehicles with less fluctuation during phone use . While we were unable to find similar differences in mean speed and mean headway mean lane offset was also significantly lower with phone use than without . A decision tree was developed to identify the factors influencing driver speed change . Results showed that drivers increased decreased or maintained speed depending on the type and duration of phone tasks the duration of the trip and the type of roadway . Greater understanding of the specific aspects of phone use and their influences on driver distraction and performance will permit the development of more effective countermeasures including legislation enforcement blocking technologies social norms education and sending Do Not Disturb messages to callers all of which will be required to mitigate continued deaths and injuries from phone use while driving . | Hierarchical coding structure was built for 52 phone distracted Shanghai NDS events. Fluctuation of speed headway and lane offset was less during phone use. Specific phone tasks demographics and context e.g. road and weather affect speed. |
S0003347219302507 | Niko Tinbergen characterized ethology as the biological study of behaviour involving four kinds of question causation ontogeny adaptive function and phyletic evolution Tinbergen 1963 | I provide a historical perspective of Tinbergen and his four questions of ethology. Namely that of causation ontogeny adaptive function and phyletic evolution. Tinbergen insisted that each question be given equal attention. That requirement continues to present an agenda for ethological aspiration. |
S0003347219303550 | Social learning can be a shortcut for acquiring locally adaptive information . Animals that live in social groups have better access to social information but gregarious and nonsocial species are also frequently exposed to social cues . Thus social learning might simply reflect an animal s general ability to learn rather than an adaptation to social living . Here we investigated social learning and the effect of frequency of social exposure in nonsocial juvenile Port Jackson sharks | Nonsocial juvenile Port Jackson sharks learnt faster with trained demonstrators. Acquisition occurred between training bouts. Social living is not a prerequisite for social learning in elasmobranchs. |
S0003347219303598 | Polyandry has been a central topic in the study of animal behaviour . Yet it is still not clear how the body weight of each sex affects the probability of female remating and what each sex gains from polyandry . Here we aimed to shed some light on these questions using the Mediterranean flour moth | Heavier moths of both sexes are of higher fecundity and greater promiscuity. Almost all virgin pairs mate regardless of weight to ensure fertilization. Probability of polyandry rises when the female and or the second male are heavier. Sperm displacement mechanisms allow each sex to gain fitness via polyandry. Two sexes play combined roles in occurrence of polyandry depending on their weight. |
S0003347219303604 | Signals of resource holding potential in dyadic contests are relatively straightforward typically reflected in the attributes of the individual including body size and resource ownership . However conveying this information is considerably more complex in social species the outcome of collective contests will be influenced by both individual and group level effects and the signal must be subsequently transmitted to the colony in order to elicit a colony response . Australian meat ants engage in collective displays where aggregations of many hundreds of pairs of workers from neighbouring colonies antennate one another while adopting a tip toe posture with the abdomen raised . These displays rarely escalate into physical contests with their typically fatal consequences . A display between two workers may cease by one worker leaving or if one displaying worker is replaced by a nestmate . We asked whether these collective displays act to convey reliable information about relative colony size . Our field experiments and observations reveal that these displays do not necessarily convey precise information about relative colony size and that it is possible for colonies to signal an exaggerated colony size at least in the short term . | Myriad workers aggregate between adjacent colonies forming a collective display. Dyadic displays between non nestmate workers rarely escalate into physical contests. Dyadic displays frequently involve one worker replacing another. Worker replacement frequency can convey information about relative colony size. Colonies can be economical with the truth about their relative colony size. |
S0003347219303616 | Femalefemale competition for mates can be as intense as malemale competition but it has received little attention until recently . Typically such competition is expressed as context dependent aggressive encounters between individuals of the same species within a complex social environment . Unlike male competition in cases of sexual parasitism female competition includes important heterospecific interactions . We explore how competitor body size and species influence femalefemale aggression in a sexualunisexual mating system where heterospecific females compete for males of the sexual species . Specifically we examined whether the size and species of female competitors and the sex and species of an audience influence femalefemale aggression in sailfin mollies | We examined femalefemale aggression in a sexualunisexual molly mating system. Body size was not as important as species in determining aggressiveness. Body size influenced tail beats species influenced the number of bites. Total aggression depended on body size species and sex of the conspecific audience. Sexual sailfin mollies received more aggression from unisexual Amazon mollies. |
S000334721930363X | Monogynous male mating strategies have repeatedly evolved in spiders along with female biased sexual size dimorphism and extreme male mating investment . As a manifestation of sexual conflict male African golden silk spiders | males are monogynous and show extreme mating investment. Female attacks and sexual cannibalism prevent a male monopolizing a female. Males that are attacked during copulation cast off legs which the female feeds on. Experimentally offering male legs to the female reduced the probability of attacks. The antipredation strategy of autotomy extended its function to pacifying females. |
S0003347219303641 | We used an automated radiotelemetry system to determine diurnal patterns of activity and temporal phenotype in female European starlings during breeding . Parental care is thought to be the most costly part of reproduction with high rates of intense activity due to foraging and provisioning for chicks so we predicted that variation in timing of activity should be closely related to breeding success . Diurnal variation in activity varied systematically with breeding stage in a way consistent with specific demands of each phase of parental care incubating females were more active late in the day 16001800 | Diurnal activity of breeding starlings varied systematically with breeding stage. There was low to moderate repeatability of temporal phenotype. Chick rearing birds were less active than incubating birds. Numerous reproductive fitness measures were independent of temporal phenotype. |
S0003347219303653 | Laterality is the prevalence of one side of the body to perform motor acts and perceptual functions . The evolution of directional biases that are consistent across individuals of a group may have been constrained by the opportunity for asymmetric animals to interact with other asymmetric animals . If we assume that social animals have more opportunity to interact with each other than solitary animals we could expect that the more social animals are the more lateralized and the more aligned they are . In precocial birds the mother is the first and most important social partner and she has a strong influence on her offspring s social motivation . We therefore wondered whether she could also influence its laterality . To see whether mothering influences the chick s laterality we compared behaviours of nonbrooded and brooded domestic chicks | Nonbrooded chicks are more lateralized and more aligned than brooded chicks. Nonbrooded chicks are more social and less emotional than brooded chicks. Cohesion and behavioural synchronization correlate with laterality strength. A multidimensional analysis shows a direct link between sociality and laterality. The more social chicks are the more lateralized they are. |
S0003347219303665 | Encountering and adaptively responding to unfamiliar or novel stimuli is a fundamental challenge facing animals and is linked to fitness . Behavioural responses to novel stimuli can differ strongly between closely related species however the ecological and evolutionary factors underlying these differences are not well understood in part because most comparative investigations have focused on only two species . In this study we investigate behavioural responses to novel environments or exploratory behaviours sampling from a total of 20 species in a previously untested vertebrate system Lake Malawi cichlid fishes which comprises hundreds of phenotypically diverse species that have diverged in the past one million years . We show generally conserved behavioural response patterns to different types of environmental stimuli in Lake Malawi cichlids spanning multiple assays and paralleling other teleost and rodent lineages . Next we demonstrate that more specific dimensions of exploratory behaviour vary strongly among Lake Malawi cichlids and that a large proportion of this variation is explained by species differences . We further show that species differences in open field behaviours are explained by microhabitat and by a major evolutionary split between the mbuna and benthic utaka radiations in Lake Malawi . Lastly we track some individuals across a subset of behavioural assays and show that patterns of behavioural covariation across contexts are characteristic of modular complex traits . Taken together our results tie ecology and evolution to natural behavioural variation and highlight Lake Malawi cichlids as a powerful system for understanding the biological basis of exploratory behaviours . | Exploratory behaviours in Lake Malawi cichlids differ strongly between species. Species differences in exploratory behaviour are explained by microhabitat. Major evolutionary radiations also explain variation in exploratory behaviours. Intermediate habitats are associated with differences in open field behaviour. Patterns of behavioural covariance across contexts are modular in Malawi cichlids. |
S0003347219303677 | Latin America was fundamental in the intellectual formation of the founders of modern biology but these pioneers directed their findings primarily to a European audience . Only later did European ethological influence reach Argentina Brazil Mexico and Venezuela . From there the study of behaviour moved to Ecuador and Colombia Brazilians and Mexicans were further influenced by networks of researchers from the U.S.A. Latin American contributions to ethology and animal behaviour are broadly visible with a few important centres especially in Brazil and Mexico . More recently there also has been a Latin American scientific diaspora mainly to Europe U.S.A. Canada and Australia with many ethologists and behavioural scientists becoming active members of the Animal Behavior Society . Latin American scholars both those who stayed in Latin America and those who are part of the diaspora have made significant scientific advances while also demonstrating an ongoing commitment to the development of science in Latin America . Information on the ethology of endemic Latin American species has provided some fundamental theoretical insights which have also enhanced ethological knowledge . | Latin America was fundamental to the intellectual formation of modern biology. European influence reached Argentina Brazil Mexico and Venezuela early on. A Latin American scientific diaspora prospers in Europe U.S.A. Canada Australia . Latin American scholars develop interdisciplinary research in ethology. Ethology of endemic Latin American species has provided key theoretical insights. |
S0003347219303689 | In insects cuticular hydrocarbon profiles are complex phenotypic traits with several functions they provide protection against pathogens and water loss and convey information about insect identity . They are particularly important in ants as they are the basis for colony specific signatures which allow nestmate recognition and thus help colonies protect their resources from competitors . Several studies have shown that levels of n alkanes are strongly influenced by the environment and that alongside methyl branched alkanes n alkanes are involved in various signalling tasks . Here we analysed the CHCs of the ant | Cuticular hydrocarbons CHCs help ants protect themselves and communicate. Levels of. alkane are strongly influenced by the environment. Variation of CHCs with elevation has consequences for nestmate recognition. Global warming may impact ant behaviour through pleiotropic traits like CHCs. |
S0003347219303690 | Understanding the sources of variation in reproductive fitness is a central goal of sexual selection research . Research investigating factors limiting male reproductive potential typically focus on limited mate availability or mate access . This focus often minimizes the potential relevance of physiological or other limitations on male reproductive potential in contrast to the emphasis on studying such limitations in females . This gap in knowledge leaves open questions about how variation in male reproductive success emerges across successive mating bouts . Here we contribute to bridging this gap by examining male reproductive potential across successive matings and across time . To reveal limits to male reproductive potential and sources of variation in these limits we measured mating rate and offspring production in | Limits to reproductive potential are surprisingly understudied in males. We allowed male flies unlimited mating opportunities to reveal reproductive limits. We found that males who mated with more females did not always sire more offspring. Females who received low quality mates remated rapidly. These findings suggest an upper bound on the reproductive success of any one male. |
S0003347219303707 | The experience of traumatic events can catalyse physiological trade offs that increase the vulnerability of organisms to disease and death . Among potential sources of trauma the arrival of new males in female philopatric species may be particularly salient due to the accompanying threat of infanticide . In such social systems the killing of dependent offspring benefits these new males by accelerating females return to receptivity . Despite widespread interest in the evolutionary drivers of infanticide there is little known about the collateral effects of male immigration on other group members . That is do the periods following male immigration act as windows of adversity that carry costs for group members over and above the direct victims of infanticide Here we examined how the immediate aftermath of new male immigration in a female philopatric species | Injury risk increased for all group members following male immigration in geladas. Dependent infants and lactating females incurred the most injuries. Injured females had longer interbirth intervals. Our results reveal a link between male immigration and female reproductive fitness. |
S0003347219303719 | Behavioural plasticity can be costly but is advantageous when it allows animals to adjust their behaviour to current conditions . Since individual differences in learning ability could be a source of differences in behavioural plasticity the frequency dependence of payoffs within a foraging group may permit the coexistence of both plastic fast learning individuals and nonplastic slow learning individuals in a frequency dependent context the adjustments of a few benefit all . In this study we investigated whether individuals that learned faster in a simple associative learning task were also more likely to adjust their behaviour in a social foraging game context than their slower learning groupmates . We measured the associative learning ability of female Bengalese finches | We examined learning speed vs behavioural plasticity during foraging in finches. Contrary to expectation slow learners were more plastic than fast learners. Thus cognitive processes involved in simple and complex tasks may differ. Effects of the fastslow continuum on plasticity may differ with social context. |
S0003347219303720 | The defensive repertoires of prey are shaped by diverse ecological and evolutionary demands . This can generate trade offs between the components of defences as in the classic fight or flight dichotomy or dedicated investment in a singular end allowing individuals in better condition to mount a more effective defence all round . Further sexual dimorphism may drive sex differences in such responses although our understanding of the interaction between sexual selection and defensive behaviour is in its infancy . Deimatic or startle defences typically combine multiple protective strategies such as camouflage and aposematism with a rapid transition between them and thus offer unique opportunities for studying the dynamics of suites of defensive behaviours . Here we examined the display of the sexually dimorphic mountain katydid | Deimatic displays seemingly provide prey with a best of both worlds defence. Mountain katydids are cryptic at rest and reveal striking colours when attacked. We tested for fight or flight trade offs and variation by experience and sex. Sexes respond differently to attack and in the trade off between display and escape. We need to consider dimorphism and condition when studying complex defences. |
S0003347219303732 | In cooperatively breeding societies dominant breeders are assisted by other individuals in raising their young . In many of these species helping behaviours and their benefits for breeders have been studied by investigating the helpers contribution to direct offspring care even though a significant proportion of help is not targeted specifically to offspring . Here we investigated how breeders and helpers share the effort in shelter maintenance and how their investment is influenced by the presence of dependent young in the cooperatively breeding cichlid | Helpers of cooperatively breeding cichlids increase reproductive success of breeders. Experimental increase in workload fosters division of labour among group members. Helpers care more in the presence of young and reduce the workload of breeders. Digging out shelters is an important investment benefiting all group members. |
S0003347219303744 | In many mammalian species males are selected to kill unrelated infants and or fetuses in order to cause lactating and pregnant females to begin cycling sooner than they otherwise would . As a result females have evolved numerous counterstrategies to prevent infanticide and feticide . One such proposed counterstrategy is the Bruce effect an apparently costly strategy in which inseminated or pregnant females cease reproductive investment in a developing embryo or fetus following exposure to nonsire males . Here I present a quantitative model that seeks to explain under what conditions females will be selected to exhibit the Bruce effect rather than risking future infanticide or feticide . I first present an analytical model of the costs of the Bruce effect relative to the costs of potential feticide or infanticide . I then test the resulting predictions using an individual based model operating under ecologically relevant conditions . The individual based model predicts that moderate and high but not low levels of infanticide can produce selection for the Bruce effect . In contrast feticide risk alone is unlikely to lead to selection for the Bruce effect although feticide risk coupled with a substantial risk of female mortality following feticidal attack can . The model correctly predicts the evolution of the Bruce effect in geladas | The Bruce effect is a purported counterstrategy to infanticide feticide by males. High risk of infanticide is sufficient for the Bruce effect to benefit females. High risk of feticide and maternal death injury are also sufficient. Many species are predicted to exhibit an as yet unreported Bruce effect or feticide. More data on fetal loss and or maternal injury following male take over are needed. |
S0003347219303768 | Female mate choice is a widespread and well recognized phenomenon . Nevertheless individual variation in female preference has not yet received the same attention although such preferences can have important effects on evolutionary dynamics . Here we assess and compare population and individual level female preferences for male ornaments and size in the tropical jumping spider | Female spiders did not show preference for male characters at the population level. Larger males sired more spiderlings. Offspring survival and feeding performance did not correlate with male characters. Female spiders showed individual preferences for male size. |
S000334721930377X | The study of vocal communication in nonhuman primates especially apes offers critical insight into the origins of human language . Although human language represents a highly derived and complex form of communication researchers have found that the organization of language follows a series of common statistical patterns known as linguistic laws . Zipf s law of brevity and Menzerath s law are pervasive across human languages and these laws have been identified in the communication of a small number of primate species . What remains less clear is whether these two laws also affect long distance vocal communication in primates . Here we provide evidence that the long distance morning calls of male gibbons cao vit gibbon | Male gibbon morning calls conform to Zipf s law of brevity and Menzerath s law. The most common notes being shortest in duration. Longer sequences are made up of shorter calls on average. |
S0003347219303781 | Sexual conflict generates a reproductive arms race that often involves behavioural adaptations of females to avoid male sexual coercion . Given the cognitive demands underlying behavioural adaptations it is surprising that there has been little exploration of whether sexual conflict plays an important role in the evolution of female brain size . Here we used a livebearing fish | Rates of male attention to females correlate with rates of female approach to males. Longer male genitalia lead to increased coercion only with large brained females. Female body size best explains avoidance of male copulation attempts. Smaller brains are better at avoiding copulations from males with longer genitalia. |
S0003347219303872 | Individuals exhibit consistent differences in behaviour and related cognitive performance . Cognitive styles based hypotheses suggest the trade off between speed and accuracy is an important factor where an individual s behavioural traits and linked decision speeds may account for its cognitive performance . The expected relationship between accuracy and decision speed however is not always clear and some studies have suggested that faster individuals do not suffer the expected cost to accuracy . Contradictory findings may be attributed to taxon specific differences but may also be due to the difficulty in separating intraindividual from interindividual variation or the use of insufficiently challenging tasks in tests . We trained archerfish | We report evidence to support the cognitive styles hypothesis in archerfish. Consistently fast fish learn to shoot novel targets quicker than slower fish. Consistently slower fish have greater discrimination success in three choice tests. Even with differential rewards two choice tests fail to reveal cognitive styles. |
S0003347219303884 | Inhibitory control is the ability to resist performing a prepotent but ultimately incorrect behaviour in situations that demand restraint . Inhibitory control is linked to brain size and intelligence in humans and animals but it is unclear just how it evolves . Inhibitory control is thought to be particularly important in complex social environments where demands can shift frequently based on the social context and the identities or behaviours of other individuals in a group . Indeed the social intelligence hypothesis suggests that the demands of living in complex social groups led to the evolution of sophisticated cognition . Here we tested inhibitory control in wild spotted hyaenas | For hyaenas living in larger groups may demand greater inhibitory control. Cohort size was a stronger predictor of inhibitory control than overall group size. Low ranking hyaenas living in larger groups had better inhibitory control. Adult male and female hyaenas did not differ in inhibitory control. Our results support the social intelligence hypothesis. |
S0003347219303896 | Mating generally occurs with adult females which undergo a suite of changes in morphology physiology and behaviour during maturation . In the brown widow spider | Mating with immature females is an alternative tactic for brown widow males. Adult females cannibalize mating males but immature females do not. Males approached and preferred to mate with adult females over receptive immatures. Males did not show a preference for unreceptive versus late stage receptive immatures. Close range cues in webs of immatures may indicate receptivity. |
S0003347219303902 | Males frequently compete for access to mates sometimes at a cost to parental behaviour and self maintenance . Theory predicts that aggressive competition among females should be less common and intense due to a trade off between competition and future reproductive investment . However the consequences of female aggression across the reproductive cycle are unknown in many species . In this study we addressed four questions about female intrasexual aggression in the house wren . Does intrasexual aggression help females during periods of increased competition over breeding resources Do aggressive females have higher quality mates Do aggressive females invest less in reproduction Does female aggression affect offspring size and survival We experimentally increased competition over nestboxes in one year by evicting a subset of birds . Females that were more aggressive during previous simulated female intrusions protected more eggs from house wren ovicide which increased following our manipulation . In two other years we monitored the mating patterns and reproductive performance of females . Aggressive females had mates that provided more direct benefits in the form of nestling provisioning . They did not invest less in reproduction and in fact provisioned their nestlings more frequently . As a result aggressive females had heavier offspring at multiple points during development . The offspring of more aggressive females were also more likely to fledge . Overall female aggression appeared to have fitness benefits directly following an experimental increase in competition and throughout the reproductive cycle in nonexperimental years . | Aggressive females protected more eggs from ovicide during increased competition. They did not invest less in egg production. Aggressive females and their mates provisioned offspring more frequently. Offspring of more aggressive females were larger at multiple points in development. They were also more likely to fledge. |
S0003347219303914 | Theory suggests that the balance between unknown dangers and novel opportunities drives the evolution of species level neophobia . Juveniles show lower neophobia than adults within mammals and birds presumably to help minimize the costs of avoiding beneficial novelty and adults tend to be more neophobic to reduce risks and focus on known stimuli . How these dynamics function in island species with fewer dangers from predators and toxic prey is not well understood . Yet predicting neophobia levels at different age classes may be highly valuable in conservation contexts such as species translocation programmes where responses to novelty can influence the effectiveness of prerelease training and animals survival postrelease . To better understand how neophobia and its age related patterns are expressed in an island corvid we surveyed object neophobia in 84 of the world s critically endangered alal | Neophobia differs by species and is often lower in young birds mammals than adults. Predicting neophobia levels is hard but can inform natural history and conservation. We measured object neophobia across the majority of an endangered crow species. All crows were neophobic but juveniles were much more neophobic than adults. We discuss the reversed age effect in relation to neophobia theory and conservation. |
S0003347219303926 | In monogamous mating systems pair mates frequently share similar characteristics such as size or ornamentation a pattern suggesting mutual mate choice . When pairs persist across multiple seasons preferences for familiar pair mates can either reinforce or disrupt patterns of assortative pairing . Snapping shrimp | Male snapping shrimp preferred larger females even during the nonreproductive season. Females preferred their current pair mate over size matched novel males. Females increased mate sampling during the nonreproductive season. Males showed no preference for current mates females showed no size preferences. Sex differences in preferences led to year round size assortative monogamy. |
S0003347219303938 | When disturbed animals use various modes of communication to alert conspecifics about the source of danger . Some species have evolved graded or continuous signals specific to the type of threats . African elephants | Asian elephants modulate both high and low frequency calls when disturbed. Duration of trumpets decreases and that of rumbles increases when disturbed. Fundamental frequency and formant positions of rumbles decrease during disturbance. Smaller groups produce longer rumbles when disturbed. |
S000334721930394X | Traditionally it has been suggested that sexual selection can cause sexual size dimorphism . However a recent review in gastropods shows that SSD itself can also cause sexual selection Ng etal . 2019 . | Dimorphism is negatively correlated with sexual selection differential in gastropods. Dimorphism plus similarity based mate choice can cause strong sexual selection. Preference bias can have the opposite effect than dimorphism on sexual selection. Past mate choice causing dimorphism cannot be estimated from present sexual selection. |
S0003347219303951 | The nonlinearity and fear hypothesis predicts that the structure of alarm vocalizations will be influenced by the signaller s internal state . Specifically stressed or otherwise more aroused individuals will produce alarm calls that are relatively more nonlinear . The position of an individual in a social network can influence an individual s sense of security . More centrally located individuals may feel more secure and thus we might expect that they would produce noisier calls . Building on previous research about the influence of social relationships on an individual s sense of security we asked whether social network position explained variation in the noisiness and goodness of pitch of alarm calls produced by trapped yellow bellied marmots | Alarm call structure is affected by an individual s social network position. Socially isolated marmots lower outstrength produce noisier alarm calls. Social relationships may influence how individuals perceive their safety. |
S0003347219304087 | Territoriality is central to animal behaviourists understanding of many facets of animal behaviour including resource acquisition space use behaviour communication and mating systems . However the term itself how it is conceptualized and defined has long been nebulous and contentious . Here we ask whether juxtaposing debates about territoriality from animal behaviour with parallel discussions of territoriality from the social sciences can offer a historically and sociologically informed path out of the conceptual gridlock in which animal territoriality has been located for decades . We delineate two key problems with territoriality identified in the animal behaviour literature First that it focuses on how animals are expected to behave rather than how they actually behave and second that it assumes rather than demonstrates the function of and specific relationships among individuals . We then link these problems to social scientists theorizations of the difference between property and access whereas property is focused on how people are expected to behave under juridicallegal rules governing resource use access focuses on a wide array of means by which people | Territoriality is a powerful framework but it is challenging to define. We delineate key problems with territoriality from the animal behaviour literature. We juxtapose debates about territoriality from animal behaviour and social science. Focusing on access and not ownership addresses key problems with territoriality. |
S0003347219304105 | Anthropogenic noise pollution is known to alter the behaviour of acoustically sensitive animals . Many animals also sense vibrations through solid substrates and use substrate borne vibrations in conspecific communication . The effects of substrate borne noise pollution however remain largely unknown . Here we investigate the potential for seismic noise to alter the reproductive behaviour of the burying beetle | Seismic noise presents a novel challenge to vibrationally sensitive animals. beetles stridulate during parental care and may sense vibrations. We measured responses to seismic noise in. Beetles stridulated throughout burial and sensed low frequency vibrations. Beetles showed reduced reproductive output in the presence of seismic noise. |
S0003347219304130 | It has been argued that the influx of women into the fields of primatology and animal behaviour caused a transformation in conventional beliefs particularly with regard to our understanding of malefemale sexual dynamics and the role of females in animal societies . Women members of the Animal Behavior Society have played important roles in challenging the accepted wisdom in our field . Simultaneously at least during the last 40 years women have become an increasingly vibrant force within the ABS including playing significant roles within the leadership of the society . As a result animal behaviour represents a notable exception with regard to gender parity when compared to some other scientific disciplines . This paper examines the synergisms between the influx of women into animal behaviour and novel advances in the field . It also addresses questions debated by feminist scholars regarding the reasons and mechanisms for women s impacts and whether feminism is a factor in disciplinary transformations . Finally it suggests the integration of women in animal behaviour provides a blueprint for inclusion of other groups under represented in the sciences . | The 1970s saw an influx of women in the fields of animal behaviour and primatology. Since then women have had major impacts on the development of animal behaviour. The Animal Behavior Society has been unusually receptive to women colleagues. |
S0003347219304142 | Geographical variation has been widely studied in oscine songbirds with particular attention paid to the interplay between variables associated with learned song and dispersal . While most field based studies have focused on discrete dialects analysing data from quickly growing citizen science libraries could uncover geographical patterns in species previously thought to exhibit random variation in song . Specifically using citizen science birdsong databases we test whether chipping sparrow | Citizen science data revealed long range geographical patterns in song features. Chipping sparrow song rate and frequency varied with longitude but not latitude. Despite early song matching diverse song types persisted across the species range. Song and genetic variation were not correlated suggesting a complex life history. |
S0003347219304154 | For many animals group living mitigates predation risk and ensures survival . However in yellow bellied marmots increased sociality is associated with lower female reproductive success decreased female longevity and increased overwinter mortality for both males and females which raises questions about the adaptive value of sociality in this facultatively social mammal . Here we used social network analysis to examine the relationship between sociality and summer survival which is almost always attributable to predation . Yearling females had enhanced survival when they had stronger social relationships and were more central in their network . Adult female survival was not associated with social network traits but females were more likely to survive the summer if they lived in larger groups . Survival of yearling and adult males was not associated with either social network trait variation or variation in group size . These findings identify a potential benefit for marmot sociality and an explanation for marmot colony social structuring . | Group living mitigates risks in many but not all species. We used social network analysis to examine benefits of group living in marmots. Yearling females with strong social relationships had higher summer survival. No other agesex cohort benefited in the same way. The benefits of sociality may vary by age and sex. |
S0003347219304166 | In mammals characterized by a mating system in which a single male monopolizes reproduction infanticide is reported to occur following a male take over often resulting in females returning to oestrus more rapidly than if their infant has survived . However over the course of a 17 year study of golden snub nosed monkeys | Infanticide is common in polygynous mammals but varies across species. We found no infanticide in a 17 year study of polygynous wild snub nosed monkeys. Social network and genetic analyses show most infants are from extrapair matings. Female golden snub nosed monkey might reduce infanticide by confusing paternity. Highly cohesive multilevel sociality may facilitate alternative reproductive tactics. |
S0003347219304178 | Toxic or noxious prey often signal their unpalatability through aposematic coloration and the evolution of aposematism has become a model system in evolutionary behaviour . Aposematic colours are not only easily recognized by predators but for many predators aposematism enhances learning and memory retention . In this study we used a visually oriented insectivorous agamid lizard | We offered different colours of dyed crickets to insectivorous lizards. Lizards attacked red crickets less often than green or black ones. We then trained new lizards to avoid dyed crickets by adding a distasteful powder. Lizards learned after a single exposure not to attack crickets regardless of colour. Lizards remembered red crickets better than green crickets up to 60 days. |
S000334721930418X | Scent marking where individuals deposit signals on objects in the environment is a common form of chemical signalling in mammals and is thought to play a critical role in maintaining social organization within wide ranging spatially dispersed populations . Senders however can incur scent marking costs through mark production time investment in patrolling and depositing maintaining mark sites and increased risk of detection by predators and prey . To mitigate these costs senders can adapt spatial patterns of scent marking to increase the probabilities of their scent marks being encountered by intended receivers . Relatively little however is known of the spatial scent marking placements of many wide ranging carnivore species with most studies focusing on scent mark form and function . Here we used detailed observational data collected from over 7 years of following individual leopards | Species can use spatial scent marking strategies to facilitate communication. Leopards showed higher investment in maintaining scent marks at home range boundaries. Communication behaviours are impacted by human modifications to the environment. Leopards are highly flexible in their scent marking strategies. GPS and focal data can provide greater insights into cryptic species behaviours. |
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