Evaluation of the effect of roadside barrier type on lateral offsets in urban highways

摘要

Since one of the most crucial elements in crashes is related to human factors, driver behavior significantly impacts road safety. Driver behavior is influenced by many factors, including driving characteristics, experience, and the road environment. In this study, the effect of combining different elements including shoulder width (left shoulder width up to 0.6 m and more than 0.6 m as well as right shoulder width up to 1 m and more than 1 m), type and height of barriers (guardrail with a height 0.7 m, New Jersey with a height of 1.1 m, and retaining walls with heights of 5 and 10 m) on driver behavior on urban highways (in both upgrade and downgrade scenarios) was investigated. For this purpose, 20 urban highway segments were selected for filming and speed recording using the laser gun camera. The results revealed that New Jerseys on the left shoulders had caused driver workload and concentration more than guardrails. An average of 5% reduction in speed and a 25% increase in the lateral offset of the barriers were recorded to reduce the driver's workload. A 10-m retaining wall has caused more driver workload and concentration on the right shoulder than the curbs. An average of 8% reduction in speed and a 36% increase in the lateral offset of the barriers were recorded to reduce the driver's workload. It was also concluded that increasing the shoulder width can reduce the driver's workload. Finally, the movement methods model was predicted by using the nonlinear regression model for different car wheel positions from lateral lanes to various road barriers.