Evaluating Traffic Congestion at DHA Phase-I Roundabout

Level of Service Assessment and Development of Simulation Models Using PTV Vissim Software

Abstract

Most junctions, especially multilane roundabouts, are facing traffic congestion due to an increase in the number of vehicles traveling through Islamabad, Pakistan. This occurs when the amount of traffic demands more space than is available. In light of Pakistan's diverse driving conditions, the topic of effective vehicular traffic modelling is still heavily contested. Improving the traffic capacity of multilane roundabout is of great significance in solving the urban traffic problems. Considering the DHA Phase 1 roundabout situated at GT Road, this study aims to present a detailed analysis of the traffic delay at this roundabout. Highway Capacity Manual (HCM) and microscopic traffic simulation software PTV Vissim were used to analyze the traffic flow. Traffic Congestion Analysis of DHA Islamabad Phase-I roundabout was carried out by determining the Level of Service and developing a simulation model using PTV Vissim software. It was observed that LOS was improved from F to D. Delay was reduced by 94.18% at Fauji Foundation Hospital, 76.09% at DHA road, 70.85% at Kacheri road and 42.11% at Bahria road. Queue Length was reduced by 100% at Fauji Foundation Hospital, 73.75% at Bahria, 68.07% at DHA and 51.42% at Kacheri road. Moreover, a solution was proposed to decrease the traffic congestion and the LOS was significantly improved.