New Capacity Model for Malaysian Urban Roads Using Macroscopic Fundamental Diagram and Multiple Linear Regression Approach

Abstract

The existing manuals used to estimate urban road capacity have limitations. Adapting these manuals to compute the road capacity at urban roads reduces estimation accuracy. This study attempts to develop a capacity model to characterize urban road capacity. Twenty-two sites consisting of the collector/distributor roads and local roads in the Cheras-Kajang area in Klang Valley are selected for traffic data collection during the morning peak hour from 8 a.m. to 9 a.m. Site video camera recording is carried out, and the traffic data is extracted from the video footage. The speed-density and flow-density curves of the macroscopic fundamental diagram are fitted with the traffic data extracted. The capacity value is then derived from these curves. The urban road capacity model, termed the UrbanCap model, is developed in this study using the multiple linear regression approach. The results show that the urban road capacity depends on the type of road and carriageway and speed limit. The comparison of the capacity values produced from the UrbanCap model with other manuals justifies that it has a better estimate than the existing manuals used in Malaysia. The results also signify a need to develop a manual/guideline to quantify the urban road capacity in Malaysia for road design and analysis.