Effect of Visual Range on Driving Speed on Low-grade Highway

Abstract

Visual range from road alignments plays an important role in traffic safety since it is a key factor for drivers to adopt an appropriate speed. It is especially true to low-grade highways where speeds tend to reach a high value when sections have a relatively good linearity. High speeds on low-grade highway are considered a main contributor to traffic accidents. This paper studied the relationship of maximum visual range and driving speed on low-grade highways to put forward a suggested visual range for safe driving. Four typically mountainous highway models with the same driving environment but different visual ranges were constructed to analyze the effect of visual range on driving speed. A driving simulator with eight degrees of freedom was used to carry out the experiments. Data of driving speed, acceleration and deceleration were collected to study the speed and acceleration trends. The conclusion drawn is that the appropriate value of maximum visual range on low-grade highways is recommended to be 80m to ensure safety driving.