Study on the Method of Traffic Status Change Time on Urban Expressway

Abstract

A method of defining traffic status change time on urban expressway was studied. Traffic situation on the expressway was analyzed under two states: congestion and non-congestion. In accordance with the traffic flow parameter adjustment accumulative curve by Daganzo, a new method for defining traffic status change time was put forward. That is, traffic status change time was judged by using adjustment accumulative curve of flow and occupancy on urban expressway. By applying the field data obtained from some urban expressways in Beijing, traffic status change time by the method meets the real situation, which confirms the validity of the method. This method can be used in identifying road traffic condition, studying traffic wave theory and evaluating incident detection.