Evaluating drivers’ speed choice with and without route-based warnings on approach to black spots on a rural highway

Abstract

A high percentage of crashes occur at black spots of rural highways, and it is of paramount importance to employ strategies that can significantly reduce these crashes. The use of warning systems is one of the different methods of achieving this goal, and this study evaluates the effectiveness of these systems in different classes of drivers. To analyze the effects of warning systems on driver performance, three speed measures (mean speed, speed variation and speed limit violation) were applied. Forty-eight male and female drivers were categorized into three age groups, namely young (18–35 years old), middle age (36–55 years old) and elderly (above 55 years old), and they were asked to drive on a rural two-lane two-way highway in the north-west of Iran to conduct the experiment. The results indicate that middle-aged men and elderly women had the highest and lowest recorded mean speeds at black spots respectively both in the warning and non-warning states. On the other hand, young male drivers had the highest speed variations in the warning state, and middle-aged male drivers recorded the lowest variations in the non-warning state. Concerning the violation of speed limit at the black spots, young and middle-aged men had the highest number of violations in the warning and non-warning states respectively. Elderly women were found to be the most cautious group both in the warning and non-warning states. Conclusively, strategies such as changing the type and number of warnings are proposed to improve the effectiveness of the warning systems in special groups of drivers.