DELAY MODELLING AT URBAN UNCONTROLLED INTERSECTIONS

Abstract

Modelling traffic flow through urban uncontrolled intersections in developing countries like India is a
complex process because of the high level heterogeneity of traffic and absence of major and minor concepts in traffic
regulation schemes. Moreover, Indian codes have not been provided any relation which can be used to directly
determine the delay at uncontrolled intersections under Indian traffic conditions.
Uncontrolled intersections are vital points on urban roads, the performance of which will influence the traffic flow
on entire network. Delays to vehicles at urban uncontrolled intersections depend upon the several factors, the most
important among these being major road approach volume, type of turning movement, and vehicular composition.
The average delay caused to vehicles is an important measure to evaluate the performance of uncontrolled
intersections. The performance of an uncontrolled intersection is described by the service delay experienced by low
priority movements. Under mixed traffic conditions, the traffic compositions, apart from the conflicting traffic volume
and proportion of turning traffic are vital factors influencing the service delay. Most of the earlier studies
conducted on this subject, pertain to homogeneous traffic environment, and only a few studies with limited scope
have been conducted under mixed traffic conditions. In this study, the service delay models have been developed for
three uncontrolled intersections located in the city. These models developed were found to be statistically and logically
sound. The level of service for the uncontrolled intersections taken under the study has been evaluated using the
estimated average service delays from the models developed.