FUNDAMENTAL STUDY ON PEDESTRIAN SAFETY AT ROUNDABOUTS BY MOVEMENT ANALYSIS

Abstract

This study discussed pedestrian safety at roundabouts by movement analysis based on video survey results at three roundabouts in Japan. First, we analyzed the speed characteristics of pedestrian at each crosswalk and conducted some statistical test from the viewpoints of intersection geometries. It is found that the existence of splitter island have effect on pedestrian crossing speed. Second, we analyzed vehicle speed at entry/exit of roundabouts by regression analyses. It is revealed that both diameter and inflow angle affect the entry speed and the setback distance between crosswalk and outer line of circular roadway impact on the exit speed. Third, we conducted some discriminant analyses for risky traffic situations near/at crosswalks. As safety check behaviors for pedestrian near/at the crosswalks, it is shown that the positioning of the pedestrian, the existence of approaching vehicle and the distance between stop line and crosswalk are related to their safety check behaviors. For the abidance of pedestrian protect rule at crosswalks for vehicles, it is revealed that the drivers for inflow traffic keep the rule when the pedestrian waits at the near-side edge of crosswalk and the drivers for outflow traffic don't keep the rule when hourly traffic volume of exit leg is increase. Furthermore, for potential risk of accidents between pedestrian and vehicles, it is found that severe conflicts tend to occur for the outflow traffic. In addition, the longer distance between crosswalk and stop line, the more severe traffic conflict. Finally, we conducted some sensitivity analyses for developed discriminant models and proposed several safety countermeasures at crosswalk for both entry and exit of roundabouts, concretely.