Modelling the major stream delay due to U-turns

Abstract

This study assesses the delay faced by approaching through vehicles at uncontrolled median openings due to U-turning movement. Under limited priority situation, the U-turning vehicles accept smaller gaps which compel the through vehicles to reduce their speeds and experience delays. First, the slowdown section is identified and the delay faced by through vehicles from the starting of slowdown section to start of median opening is estimated. This is termed as approach delay. The approaching vehicles shift laterally as they approach toward the median opening. The concept of zone has been introduced to study this lateral movement. This study shows that the vehicles moving through the zone adjacent to curb face more delay as compared to the vehicles moving through the zone adjacent to median. Finally, a regression model is developed for estimating approach delay faced by any vehicle category traveling through a particular zone at a given U-turning traffic volume.

Keywords:

• Approach delay
• median opening
• mixed traffic
• U-turns
• regression
• dummy variable