Abstract:
The rapid development of Colombo city has resulted in growth in urban traffic. The arterial roads
that provide accessibility to Colombo city are experiencing traffic congestions, especially during
peak times. The vehicles that enter these arterial roads through closely spaced access roads and
exiting vehicles to access roads from the arterial, can be considered as major contributors to
causing traffic congestion. This paper analyses how the close-distance access roads affect the
traffic flow on arterial roads. A virtual scenario for a 1 km multi-lane arterial road section with
separated two lanes in one direction and access roads were connected from the both sides of the
arterial road, was created in VISSIM software based on a case study of Galle-Colombo arterial
road to replicate local conditions. The flow rate on the arterial road was varied to understand the
total delay of the network system and the flow rate of the major arterial roads with varying access
road distances. Furthermore, an identification of the combined impact that can occur within the
road network was evaluated by defining an index. The index was defined by considering the total
delay of the network system and the flow rates of the major arterials. The recommended distance
between access roads to arterial roads was identified as a part of the study. It is recommended that
access roads may connect with a minimum of 250-275 m distance between their center lines in a
1 km arterial road section for 1000 veh/hr to 4000 veh/hr volume of arterial flow. One of the
findings of this study was when future planners designing urban road network systems, access
roads should be connected maintaining the above-mentioned distance range between their center
lines, regardless of the vehicle volume of arterial roads, to minimize total delay of the road network
and maximize the through vehicle flow of arterial roads.
Citation:
Kaumal, T.H.M.M., & De Silva, D. (2021). Study of the impact to the traffic flow on arterial roads in Colombo due to close distance access roads [Abstract]. In P. Hettiarachchi (Ed.), Proceedings of Civil Engineering Research Symposium 2021 (p. 46). Department of Civil Engineering, University of Moratuwa.