MS Thesis

Left-turn elimination network analysis

Abstract

Left-turn movement volume takes small percentage of approach volume, however case delay to the majority of traffic flow at an intersection. Left-turn movement has longest averaged delay at an intersection itself. The idea of eliminating left-turn movement is to force a small number of left-turn trips to re-routing, as a results, all other trips would have less delay at an intersection. Elimination of some left-turn movements at a defined network may help improving network performance in term of network travel time, thus, a higher level of system optimization can be achieved. A network analysis is performed to compare network performance before and after left-turn elimination applied. Traffic assignment result is expected to be different because of trips re-routing after left-turn elimination.. Intersection control delay is expected to decrease at the intersection that where left-turn elimination is applied. As a result, network travel time is expected to drop because of the saving at intersection control delay. Signalized intersection control delay is a key of this study. Trips re-routing may happen because of prohibited left-turn movement, as well as the difference in turn penalty per movement if it is assigned, which would affect shortest path calculation. Trip re-routing may cause increase in total turn movement volume in network.