Theoretical and Simulation-Based Analysis of Diverging Diamond Interchanges in China

摘要

DDI (Diverging Diamond Interchange) as an improved diamond interchange type is getting increasing use across the United States, however, its operational performance and feasibility in China remains unclear. This paper, combined with Chinese traffic conditions, presents operational performance evaluation and feasibility analysis of DDIs. It proposes a mathematical methodology, which could determine the capacity and level of service of DDIs, with critical movement theories. Besides, it compares the network performance of DDIs, improved and conventional diamond interchanges in VISSIM, and analyzes the crash data to obtain the applied condition of DDIs. The results show that the critical movement based evaluation procedure is a quick and reliable method to analyze DDIs in a planning stage, and DDIs are appropriate treatments to replace domestic over-capacity diamond interchanges, especially for locations with high left-turn demands to and from the freeway.