Delay Time Analysis and Modelling of Signalised Intersections using Global Positioning System (GPS) Receivers

Abstract

Delays at signalised intersection are considered the most important measure of effectiveness (MOE) for signalised intersections as these are used to determine the level of service (LOS). Thus, the aim of this research is the estimation of total delay and modelling of signalised intersections in Baghdad along the Palestine arterial street. Global Positioning System (GPS) receivers provide an opportunity to accurately measure intersection delay in terms of deceleration delay, stopped delay, and acceleration delay. The field data were collected for the selected sections of Palestine arterial street for Bab Al Moatham; AlSakhara; Beirut; and Maysaloon intersections respectively. Congestion of traffic conditions takes place during peak hours of the day, so from 12:00 to 3:00 p.m. on Mondays and Tuesdays in May 2019 were selected to study the variations of total travel time and travel delay times for each intersection in the selected sites. GPS essential measurement equipment running on cell phones was applied to compute the delay components for each group’s set of data points recorded at peak periods on each selected intersection corridor. A total of 60 test runs were carried out in the north and south direction in each case. The obtained results indicated that the stopping time for vehicles represents the major part of total control delay reaching about 88% of the control delay at some signalised intersections (Beirut and Bab Al Moatham intersections) at peak hours. The acceleration delay time was also higher than the deceleration delay time. GPS was also shown to be an effective field tool to accurately measure intersection delay as composed of deceleration delay, stopped delay, and acceleration delay for oversaturated traffic conditions.