Investigation on the operation effect of expressway deceleration marking based on field driving test
The present paper is inclined to explore the influence of deceleration marking lines on the longitudinal running characteristics of small passenger cars on highways and to clarify the deceleration effect of these markings.Field driving tests are conducted on three deceleration marking sections of the G50 Shanghai-Chongqing Expressway in Chongqing.We collected data including vehicle speed,acceleration,and trajectory under natural driving conditions.Through these data,we compare and analyze the overall speed characteristics,amplitude distribution,and change patterns of the vehicle when passing through three deceleration marking sections.Afterward,according to the combination diagram of velocity and acceleration and the longitudinal deceleration marking,we set the maximum decrease of velocity in the section and the velocity difference between the starting and ending points,and use the t-test method to evaluate the implementation effect of deceleration markings.The results show that there are differences in the overall speed characteristics and variation patterns of vehicles passing through the three deceleration marking sections due to differences in road geometry.The speed of vehicles on the curved slope combination road section fluctuates and changes in a five-stage pattern of"near-constant speed-deceleration-acceleration-stability-acceleration",The flat slope section is divided into two stages of"near-uniform speed-deceleration",The downhill section is divided into two stages of"acceleration-deceleration".The median and 85th percentile values of deceleration are 0.123 m/s2,0.225 m/s2,0.185 m/s2 and 0.346 m/s2,0.513 m/s2,0.489 m/s2.The speed control effect of the curved slope combination section and the downhill section is better than that of the flat slope section.All in all,the deceleration marking lines had two main effects:It can significantly reduce the operating speed of vehicles,or effectively suppress the trend of increasing vehicle speed.The research results provide basic data support for the evaluation of the effectiveness of deceleration marking lines on highways and for improving road safety.
NETL
NSTL
万方数据
维普
