Development of Delay Model for Selected Signalized Intersections at CBD in Sulaymaniyah City

Abstract

The purpose of this research is to develop an empirical model for delay prediction at Signalized Intersections as a function of influence traffic and geometric features. Two Signalized Intersections with different characteristics are selected in Sulaymaniyah city. Field traffic volumes, signal timings and phasing and control delay were measured during peak and off-peak periods using video recording technique. Geometric design elements were measured through a field survey and satellite image. A statistical approach is used to develop delay model (linear regression model with 95%). The statistical analysis indicates that both geometric and traffic variables have a significant effect on delay time. The regression model, developed to estimate delay, shows the good correlation with field values. The ratio of total width of exit roadway of intersection for traffic departing straight forward to total width of lane groups departing to the same exit roadway at the same phase at stop line (We/Ws) appear to affect the delay. The ratio has a negative effect on delay time when the ratio is less than 1.0. The model has been compared with SYNCHRO delay model. It is found that although SYNCHRO delay overestimates delay at high ) v/c ( range, but it does not have a significant difference with the field delay at 95% confidence level.