A Study Of The Capacity Of Signalized Intersection With Work Zone Based On Modeling And Simulation

With the maintenance activities of Pipelines, cables, roads and subway construction, the phenomenon of road occupation is universal and it has brought negative impact on urban traffic. However, the current research mainly focuses on work zones of highway, and the study on urban work zones is scarce. Therefore, analyzing the influence of work zone setting on traffic flow and capacity of urban signalized intersection constitutes the study.By surveying and analyzing the characteristics of work zones, two phase cross-intersection was chosen as the research object and it was divided into two categories, straddling work zone and island work zone respectively. The following factors that may have significant influence on the capacity of signalized intersection with work zone were discussed, which are heavy vehicles proportion, work zone size, etc. For the straddling work zone, the factors which have significant effect on the saturated flow rate of the straddling work zone are found by using correlation analysis and stepwise regression analysis. Then 2 models of calculating the capacity of straddling work zone were proposed including multiple linear regression model and saturated flow rate model. Further, the collected data was used to evaluate the performance of the two models. The results show that the multiple linear regress model has better performance than the saturated flow rate model, and it can truly reflect the relationship between the capacity of straddling work zone and the work zone’s geometric feature.For the island work zone, considering the complexity of traffic flow in urban intersection and the constraint of data, a mixed traffic flow model based on social force theory was proposed. It can better reflect the micro motion of vehicles, and it is applicable for heterogeneous traffic flow composed of non-motor vehicles, cars and buses. Then a case study was done by choosing a typical signalized intersection with island work zone. By using the collected data, the model was calibrated and evaluated. The results show that the simulation data by proposed model has small errors with measured data. It has certain reference value in traffic flow simulation of island work zone.Based on the calibrated model, simulations are conducted to investigate the traffic flow variation with the changing of characteristics of island work zone, such as the proportion of heavy vehicles, arrival rate of motor vehicles and non-motor vehicles, the size and position of work zone, etc. The results show that the following factors have significant influence on the traffic flow of island work zone, which are the distance from lower boundary to central belt of entrance lane, heavy vehicles proportion, arrival rate of motor and non-motor vehicles. The distance from the work zone to stop line of entrance lane significantly affects the speed of vehicles passing the intersection in an average single period. The closer island work zone is to the export, the longer it takes for vehicles to pass through the crossing, so it needs to increase the yellow time to reduce interference on the traffic flow of the other direction.