Comparison between Diverging Diamond Interchange and Conventional Diamond Interchange: Case Study in Riyadh City

The road users usually suffer from several kinds of congestion and delay especially at intersections. The traffic flow congestion due to increasing traffic volumes can be decreased by implementing some suitable alternative designs of interchanges such as diverging diamond interchange (DDI) and conventional diamond interchange (CDI). In this paper, a comparison between the DDI and CDI in traffic conditions in Riyadh city is conducted. The analysis involved different measures of effectiveness that includes delay, queue length, and number of stops. In this context, each interchange type was evaluated for traffic volumes at certain peak hours using micro-simulation program named as “Synchro”. The finding of this study shows that DDI provides a better result when compared with CDI in terms of delay, queue length and number of stops. The control delay for the DDI is approximately one third of the CDI. Also, the queue length for the DDI is about one half of the CDI. Furthermore, the number of stops for the DDI is as one half as the CDI.