SSAM을 이용한 LPI 분석

Abstract

In this thesis, a methodology using the VISSIM simulation model and surrogate safety assessment model (SSAM) was utilized to quantify the impacts of the leading pedestrian interval (LPI). It was found that the modeling of right-turn vehicles and pedestrians is the most essential factor affecting the realistic behaviors. In order to model the realistic conflicts between right-turn vehicles and pedestrians in VISSIM, the properties of the links and connectors representing crosswalk and right-most lane should be properly set. Specifically, the connector on which right-turn vehicles run should be overlaid with the link representing crosswalk. Given the developed simulation model, the impacts of the LPI were systematically quantified. After the runs of VISSIM simulation models, the conflict analysis was conducted by using SSAM. The results show that the number of conflicts between right-turn vehicles and pedestrians significantly decreases after the LPI is implemented. Additionally, It is noted that the 7 seconds of the LPI duration results in the most effective result that the other LPI durations. Finally, the impacts of the LPI were quantified when it is implemented in the major intersections in Gwangju. The impacts were varied based on the geometric features of the intersections. The average decrease in the number of conflicts was 84, which corresponds to 97%. There was a limitation in assessing the impacts of the LPI in Gwangju. That is the lack of the calibration of the simulation models in terms of the number of conflicts. For future research, this issue should be properly considered to precisely assess the impacts.