低照度环境城市道路可变限速确定

o analyze driver' recognition time of targets under low illumination environment, and provide a theoretical basis for the variable speed limit in different illumination environment. Experimental research on driver' recognition time of 6 colours target affected by environment illumination was conducted, and these data was analyzed by statistical analysis. A significant negative correlation between driver's recognition time and environment illumination was discovered. and the goodness-of-fit of the linear model reaches higher degree. Lastly, According to the recognition time of each illumination sections, and considering the relationship of vehicle braking safety distance in different illumination sections based on 500lx,a variable speed limits scheme based on low illumination environment was proposed: the normal speed limit was conducted under illumination more than 500lx; illumination in the 0~200lx and 500~500lx sections, the speed limit can be taken 70% and 80% respectively.