Effects Of Real-time Traffic Information On Driving Under Behaviors Connected Vehicle Environments

The emergence of connected vehicle(CV)technologies has made it feasible to share information between vehicles and between vehicles and surrounding environments.The information sharing,as an active intervention,has been demonstrated as an effective way to assist drivers in avoiding traffic accidents.However,due to the uniqueness between drivers,they may have distinctive reactions in term of concerning,understanding and responding the information.In order to identify these differences,this paper explores the heterogenous effects of real-time information on driving intentions and behaviors.These work are achieved by the combination of theoretical investigation and experimental verification.For example,from the perspective of driver psychology and behaviors,the differences in the factors affecting driving intentions has been explored with the information provided by the CV technologies.Multiple advanced driving assistance systems(ADASs)have been selected and utilized to establish a new system,and the rationality of this new system has been tested.The new system is built for testing the heterogeneity of driving behaviors between drivers under the CV environments.Several human-machine interfaces(HMI)have been designed for the new system,and the influences of the HMI acting on driving behaviors have been explored.The technical work of his paper include three aspects,which are introduced in detail as following.First,an improved theory has been proposed by considering heterogeneity between drivers in the extended theory of planned behavior.Based on which,the relationships among seven variables have been assumed when drivers receive the real-time information under the CV environment.These variables include driver attitudes,subjective norms,risk perceptions,perceived behavior control,driving intentions,characteristics and driving experiences.An integral model consisting of a structural equation model(SEM)and a multiple indicators multiple cause(MIMIC)has been proposed and used to test the proposed theory and these assumptions.Additionally,drivers with similar driving styles are clustered together by the clustering analysis,and the differences in behaviors between different clusters have been analyzed.Results show that the proposed theory is reasonable.Drivers have different driving intentions after they received the real-time traffic information provided by CV technologies.Then,to verify the heterogeneious impacts of information on driving behaviors and intentions,a new system is built for testing the heterogeneity of driving behaviors between drivers under the CV environments.This system is achieved by selecting ADASs and its warning indicators,caculating warning conditions of ADASs,and determining the release priority of information provided by ADASs.Seven ADASs have been selected and used to establish this new system,including collision warning,lane change warning,curve speed warning,emergent information warning,car-following guidance,variable speed limit and service notification.In light of the functions,these seven ADASs are re-classified into three categories,including safety information warning,efficiency information notification and service information notification.The information release priority of these seven systems is set by the principle of considering the safety first,followed by the efficiency and service.Afterwards,based on the data collected from field tests and questionnaire surveys,the differences in driving behaviors have been analyzes after drivers receive respective simple warning information and the information provided by the new system.Results show that the rationality of the new system has been tested.Finally,based on the information release priority of the new system built above,three kinds of HMI have been designed.Eight scenarios have been designed,including rear-end collision warning,later collision warning,forward collision warning,lane change warning,curve speed warning,emergent events warning,car-following guidance,and variable speed limit.The data on driving behaviors and subjective perception ranking have been collected in the eight scenarios.After data collection,driver subjective perception ranking,the different effects of three kinds of HMI on driving behaviors and the different effects of HMI on driving behaviors between drivers are analyzed.Results show that drivers with various driving ages or annual driving mileages or driving styles have significant differences in driving behaviors when they are exposed to different HMI.The findings can guide the development and integration of new ADASs under the CV environment,and also provides a theoretical basis to optimize the HMI design and realize the personalized information service.