Improving Road Traffic Conditions by Using Simulation Models : Case study of the roundabout Ali Ebn Taleb in Alexandria, Egypt

Abstract: The roundabout is very congested causing long queues. Data collection was made 2 of May between07.30-08.30. Data was only collected during the morning of 2 of May due to the small amount of timebefore the academic year end. The data collected did not represent peak hour conditions in theroundabout due to the data collection being made between holidays. To create peak hour conditions afactor was used to create more representative data. Missing information was an issue however, it wasdealt with by using an iterative fitting process to model rout choices in the roundabout.Models were made in PVT VISSIM and Synchro 10 with the application Sim traffic. The basic modelscould not be validated as data collection was made at one time only. The models were calibrated usingthe collected data from the morning of the 2 of May. Two scenarios were made in the software, onewhere the roundabout was turned in to a signalised roundabout and the other where it was turned intoan intersection. The results from the comparison between the scenarios shows an improvement of theconditions both cases regarding delay, speed and traffic flow going into the roundabout. Due to thebasic model not being validated the conclusions made from the alternative solutions must be madecarefully. The biggest improvements can be seen in the alternative to make the roundabout into anintersection in both software, indicating that turning the roundabout in to an intersection would lead tothe biggest improvements in the traffic conditions of the roundabout.