A VISSIM SIMULATION APPROACH TO ENHANCE LEVEL OF SERVICE OF CLOVERLEAF INTERCHANGES AT GREATER CAIRO

Abstract

This study examines the effect of application of different “Ramp Metering” techniques on selected cloverleaf interchanges in Greater Cairo-Ring Road. Several site investigations and surveys were conducted to determine the geometric characteristics of cloverleaf interchanges of Greater Cairo-Ring Road then these interchanges were grouped based on their characteristics and one interchange was randomly selected from each group. Further site surveys were conducted to collect data about the traffic volumes of the selected interchanges. Using these data, a microsimulation model was developed using VISSIM software to assess the current conditions of traffic operation and the effect of applying different “Ramp Metering” techniques. The results were presented in terms of measures of performance such as level of service, time of delay and average vehicles speeds. Two “Ramp Metering” techniques were applied (fixed rate “Ramp Metering” and ALINEA algorithm “Ramp Metering”). Each technique was applied with different scenarios and parameters.