Abstract:
In order to set the speed limit standard on freeway in daytime and nighttime and to ensure enough time for drivers to acquire information, the data of driver's recognition distance in daytime and nighttime were compared and analyzed using mathematical statistics and regression analysis methods. By studying the quantitative impacts of driving speed, horizontal curve radius, and longitudinal slope on driver's recognition distance in daytime and nighttime, models were established for the relationship among driver's recognition distance, driving speed, horizontal curve radius, and longitudinal slope. The results show that the driver's recognition distance in nighttime decreases by 8.5% averagely and 30.4% maximally compared with that in daytime. The decreasing rate is affected by driving speed and highway alignment. The relationship between driver's recognition distance in daytime and driving speed, horizontal curve radius, and longitudinal slope are negative logarithmic, positive linear,and negative exponential, respectively; and model's R-square is 0.852. In contrast, the relationship between driver's recognition distance in nighttime and driving speed, horizontal curve radius, longitudinal slope are negative linear, positive logarithmic, and negative exponential, respectively; and model's R-square is 0.983.