Impact of stretching-segment on saturated flow rate of signalized intersection using cellular automation

• Published in: Journal of Central South University 2013-10, Vol.20 (10), p.2887-2896
• Main Authors: Li, Yan, Chen, Kuan-min, Guo, Xiu-cheng
• Format: Article
• Language: English
• Subjects: Engineering; Metallic Materials
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-013-1810-6

In order to analyze the impact of stretching-segment on the saturated flow rate of signalized intersection approach, an improved cellular automation model was proposed to estimate its saturated flow rate. The NaSch model was improved by adding different slow probabilities, turning deceleration rules and modified lane changing rules. The relationship between the saturated flow rate of stretching-segments and adjacent lanes was tested in numerical simulation. The length of stretching-segment, cycle length and green time were selected as impact factors of the cellular automation model. The simulation result indicates that the geometrics design of stretching-segment and the traffic signal timing scenario have major effects on the saturated flow rate of the intersection approach. The saturated flow rate will continually increase with increasing stretching-segment length until it reaches a threshold. After reaching the threshold, the stretching-segment can be treated as a separate lane. The green time is approximately linearly related to the threshold length of the stretching-segment. An optimum cycle length exists when the length of the stretching-segment is not long enough, and it is approximately linearly related to the length of stretching-segment.