DEVELOPMENTOF CAPACITY AND DELAY MODEL FOR UNCONTROLLED MEDIAN OPENINGS UNDER MIXED TRAFFIC CONDITION

Abstract

Establishment of un-signalized median openings have expanded in numerous urban districts of cities in India. The thought process behind this establishment is to take out issues connected with illicit U-turns occurring at crossing points and other transportation facilities near these median openings on multi-lane urban streets. Most of the median openings in India are uncontrolled and un-signalized. The goal of this study is to develop a procedure for developing the capacity of U-turn movement at median openings on multilane highways. Data were collected at five selected median openings in the city Hyderabad. Data were collected in peak hours using video recording technique at the selected sections, which are free from gradient, curves, on street parking, pedestrian movement and effect non-motorized vehicles. Normally, the speed of conflicting traffic stream is relatively high and the turning vehicle must wait for accepted gap and then turn under low speed level. Therefore, the turning vehicle needs large gap in the conflicting stream before performing the U-turn. In fact, the little studies, which contain procedures and models for estimating capacity and delay for different movements at un-signalized intersections, do not provide specific guidelines for estimating capacity and delay of U-turn movement at median openings. For this reason, an effort was made to estimate capacity and delay at U-turn median openings. In this study, empirical approach is used to estimate capacity of U-turn movement at median openings of divided arterials. The empirical approach using regression analysis was adopted to estimate the best form of the predictive equation for the U-turn capacity and investigate the effect of different relevant factors that might affect the stimated capacity. The results of the approach are presented in this study. A linear model was also recommended as a relationship between the average total delay of the U- turning vehicles and the conflicting traffic flow.