Study And Modeling On Vehicle Operating Safety Characteristics

The research on the traffic safety characteristics of the vehicles has become oneof the hot spot in the domain of transportation. In the traffic system including"people-vehicle-road-environment", the driver is the main receiver and processor ofthe information, and is also the core of traffic system. In complex traffic scenes, thedriver is likely to make wrong forecast and judgment for the car-following behaviorand the lane-changing decision as a result of leading vehicles into potential dangerand causing traffic accidents. So studying the traffic safety characteristics of the ve-hicles is particularly important.This paper analyzes and summarizes the traffic characteristics of the vehicles atdifferent traffic flow states, and studies the safety characteristics of vehicle operating.Based on the distribution data of the lateral position of vehicles in urban expressway,considering the car-following lateral interference, the influence of the lateral space onthe following vehicle is analyzed and the staggered car-following model is set up.Furthermore, this paper studies the reasons and types of lane-changing behavior, andputs forward the conditions avoiding collision with the application of the dynamicscharacteristics of the target vehicle and the surrounding vehicles in the lane-changingprocess, establishes the model of the minimum longitudinal safety distance, definesthe safety area and the unsafe area, introduces the concept of demand safe distance,combines the lane-changing behavior with the car-following behavior through initialexpectation spacing model to make the car-following behavior and the lane-changingbehavior shifting safely. Moreover, based on the above research, this paper sets up theframework of integrated model vehicle travels, and it is based on the concept ofshort-term goal and short-term plan. Meanwhile, considering acceleration andlane-changing behavior, the interdependence among decisions is emphasized. Driver’sshort-term goal is defined by the target lane, and the driver expects to change lane butcannot immediately change, consequently choose a short-term plan to accomplish theexpected changing lane. While short-term plan is defined by every gap of the targetlane, the driver uses the target gap to adjust the accelerated/decelerated speed toachieve changing lane. In this paper, we simulated the driving track of the followingcar under different values of the FC, reproduced the interference scene of the lateralcar on the target car. The model of minimum longitudinal safe distance is conducted for numerical simulation, and it is concluded that before changing the lane, adjustingits speed and the space with the surrounding vehicle can help enter into the safelane-changing area, accordingly completes the driving goal.