Pavement markings have definite functions in a proper traffic control system. They are applied for the purposes of regulating and guiding the movement of traffic, and promoting safety without diverting the driver’s attention from the roadway. It was observed that pavement markings located to the right of the car are detected more easily and at distances farther away when compared with the corresponding markings placed to the left of the car. However, compared to other types of longitudinal markings, the effect of edge lines on safety and driver behavior has been much less investigated. The conducted crash statistic analysis found that edge-line treatments on rural two-lane roadways may reduce accident frequency up to 26 percent and the highest safety impacts occur on curved segments of roadways with lane widths of 9 to 10 feet. The next stage was focused on complex investigations of edge lines impacts on driver behavior and reactions, including vehicle navigational and positioning issues, speed selection, and effect on driver visual perception. Stationary traffic observation, test driving, and several laboratory experiments were conducted on the selected rural two-lane highways with different roadway width before and after edge lines placement. Studies indicated that edge line treatments: - increase speed on average by 5 mph or 9 percent on both straight and curved highway segments; - moves vehicles toward the pavement edge at both daylight and darkness in an average of 20 inches; - reduce vehicle fluctuation around trajectory center line by 20 percent; - reduce driver mental workload; - improve driver’s estimation of roadway curvature; - increase driver’s advance time of intersection identification. (Author/publisher)
Samenvatting