Capacity estimation model on weaving segments of urban expressway

In order to investigate the characteristics and influencing factors of capacity on the weaving segments of urban expressway, based on traffic flow detector data in one year, 20 available weaving sites were selected from 60 typical weaving segments on the expressways in Shanghai according to the flow-speed curves. Then the capacities of weaving segments were calculated through statistical analysis, and the impacts of the typical factors on capacity were analyzed as well. Finally, new estimation model which is suitable for the characteristics of urban expressway weaving segments was proposed. Three different capacity estimation models (HCM2010 regression model, theoretical model and the new model) were also compared and analyzed. The results show that the estimation error of the new model (3.6%), is smaller than that of HCM2010 model (10.4%) and the theoretical model (25%). The logarithmic function relationship exists between the weaving volume ratio (RV), diverging volume ratio and capacity, while the linear relationship between the weaving length, lane number and capacity. The new model has better applicability, especially for the situation when the value of RV is relatively high which is also more consistent with the operation characteristics of weaving segments on urban expressway. © 2016, Editorial Department of China Journal of Highway and Transport. All right reserved.