Evaluation the level of service at a roundabout : A case study on Al-Ibrahimeya roundabout in Alexandria, Egypt

Sammanfattning: The capacity of today’s transportation network in Alexandria cannot handle the increasing number of vehicles. The root of traffic congestion in Alexandria is most likely as result of urban planning failure, an inadequate public transportation network, strong population growth, lack of enforcement of traffic laws, complex spatial street network and poor road quality.The aim with this thesis is to simulate various traffic scenarios for the purpose of studying, evaluating and improving the traffic conditions on the intersection Al-Ibrahimeya, however, for long-term efficiency and improvement in Al-Ibrahimeya, the traffic conditions in the entire system be improved.In this thesis, a model was built in the microscopic software VISSIM and macroscopic software SYNCHRO. The model is calibrated based on data collected from video recording. Two alternative solutions to overcome the congested traffic conditions were tested. Signalization has been the main alternative solution performed for intersection Al- Ibrahimeya.The simulation results showed some improvements in terms of delay and travel time. Roundabouts are usually suitable for under low to mid traffic conditions. When there is a heavy traffic flow, as in this case, roundabouts are not suitable and may cause problem in the network. Implementing signals led to some decrease in the entering and exiting flows because the total network became more controlled. However, an organized and well-functioning signalization program helped to reduce delay and travel time in most of routes.