Model and Simulation of the Traffic of the Urban Signalized Intersection with Island Work Zone

Work zones exist widely in cities of many countries and have a significant negative impact on city traffic; however, the majority of existing studies focused on freeway work zones, work zones on urban arterials have not been investigated carefully. For the first time, this paper focuses on a specific type of work zone that is located within the area of a signalized intersection, namely, island work zone, and a novel traffic flow model for the island work zone traffic flow is proposed by improving the existing social force model in the paper. Compared to the existing traffic flow models, such as the car-following and lane-changing models, the proposed model can capture the special traffic flow characteristics of the island work zone, including the heterogeneity, no lane division, and irregular boundary. Field data collected in Chengdu, China is used to calibrate and validate the proposed model. Simulations are also conducted to investigate the variations of the vehicle number and average speed for different work zone features and traffic flow characteristics. The results display that the model can replicate the heterogeneous traffic flow of the intersection with island work zone with high performance. When an island work zone is located close to the intersection exit, the entered vehicles are blocked before the exit, so the yellow time should be extended to ensure all the entered vehicles can pass the intersection. When a work zone occupies over one meter of the median divider, its impact on the traffic flow will become much significant.