Operating speed is an indispensable index for evaluating the alignment quality and project safety of highway. In order to ensure coordination and smoothness of speed transition near exit of expressway, the operating speed model for passenger car on deceleration lane was studied. Drone and image processing technique were adopted to collect the data of vehicle speed at exits of ring expressway in Nanjing, and the minimum sample size was determined. Then, K-S test was performed to examine the normality of speed distribution at the featured points, and variation characteristics of speed with travel distance were illustrated. Furthermore, the prediction models of operating speed for passenger car at diversion point and shunting nose point were proposed respectively. Finally, the two models were validated through statistical tests. The results show that the two models could effectively predict the operating speed of passenger car at featured points on deceleration lane, and the prediction meets the requirements for application. Especially, In addition to the length of tapered section and deceleration section, ratio of these two sections also plays a significant role in predicting operating speed.

CICTP