Adaptive signal control and coordination for urban traffic control in a connected vehicle environment: A review

Existing signal control systems for urban traffic are usually based on traffic flow data from fixed location detectors.Because of rapid advances in emerging vehicular communication,connected vehicle(CV)-based signal control demonstrates significant improvements over existing conventional signal control systems.Though various CV-based signal control systems have been investigated in the past decades,these approaches still have many issues and drawbacks to overcome.We summarize typical components and structures of these existing CV-based urban traffic signal control systems and digest several important issues from the summarized vital concepts.Last,future research directions are discussed with some suggestions.We hope this survey can facilitate the connected and automated vehicle and transportation research community to efficiently approach next-generation urban traffic signal control methods and systems.

Prediction of instantaneous driving safety in emergency scenarios based on connected vehicle basic safety messages

Purpose–Basic safety message(BSM)is a core subset of standard protocols for connected vehicle system to transmit related safety information via vehicle-to-vehicle(V2V)and vehicle-to-infrastructure(V2I).Although some safety prototypes of connected vehicle have been proposed with effective strategies,few of them are fully evaluated in terms of the significance of BSM messages on performance of safety applications when in emergency.Design/methodology/approach–To address this problem,a data fusion method is proposed to capture the vehicle crash risk by extracting critical information from raw BSMs data,such as driver volition,vehicle speed,hard accelerations and braking.Thereafter,a classification model based on information-entropy and variable precision rough set(VPRS)is used for assessing the instantaneous driving safety by fusing the BSMs data fromfield test,and predicting the vehicle crash risk level with the driver emergency maneuvers in the next short term.Findings–Thefindings and implications are discussed for developing an improved warning and driving assistant system by using BSMs messages.Originality/value–Thefindings of this study are relevant to incorporation of alerts,warnings and control assists in V2V applications of connected vehicles.Such applications can help drivers identify situations where surrounding drivers are volatile,and they may avoid dangers by taking defensive actions.