A Study of Scramble Timing Phase at Isolated Intersections

• Main Authors: WENG, YEN-FEN, 翁燕芬
• Other Authors: 曹壽民
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/59776656864541166567

碩士 === 國立臺灣大學 === 土木工程學研究所 === 91 === The objective of this research is to establish an evaluating procedure for adopting scramble timing for pedestrians at a signalized intersection. The scramble timing is a signal phasing design, which provides pedestrians with a short period of exclusive time of use of an intersection. During that phase, pedestrians can cross the intersection in all directions, even diagonally. In this research, a performance index of generalized cost is used to integrate evaluation criteria of safety and efficiency of a signalized intersection. Efficiency is expressed in terms of pedestrian delay and vehicle delay. Safety is expressed by the expected conflicts between pedestrians and vehicles. Delays and conflicts are further expressed in monetary term by adopting average national income and value of life, respectively. A computerized traffic model, VISSIM, is adopted to simulate road user behavior. The concepts of row-pedestrian-equivalent and line-pedestrian-equivalent are adopted to determine pedestrian-vehicle conflicts. Results of statistical analyses show that three decision variables are most critical in affecting the performance of the signal phase design. They are vehicle volume, pedestrian volume, and the ratio of right-turning vehicle to total number of vehicles. The research demonstrates that scramble timing phase would be a good design at intersections with high pedestrian volume, high right-turning vehicle ratio and low through traffic volume.