Effects of non-motorized vehicle on speed-density relationship of an urban intersection

Khondhaker Al Momin; Shahrin Islam; Saurav Barua

Abstract

The study investigated the influence of non-motorized vehicle (NMV) in the heterogeneous traffic in terms of speed–density (v-k) relationship. The traffic of a busy intersection of Dhaka city was studied, conducted traffic survey, and modelled using VISSIM software. Three traffic scenarios, existing traffic (M1), 20% increase of NMV (M2) and 50% increase of NMV (M3) were simulated. Then, the dataset was used to model the linear v-k relationship. The v-k lines were shifted downward with the increase of %NMV. 15.28% and 38.00% decrease of free flow speed and 14.04% and 24.62% increase of jam density was measured in M2 and M3 scenarios compare to that of M1. Vis-à-vis, increase of controlled numbers of NMV caused overall reduction of vehicle speed, increase of wait time, traffic jam and loss of travel time, which is inconvenience to the road users. Installation of separate NMV lane was suggested to improve the existing traffic condition in the city.Keywords: Non-motorized vehicle, heterogeneous traffic, speed–density relationship, free flow speed, jam density