Operational Performance Comparison between Three Unconventional Intersection Designs: Left-turn Bypass, Diverging Flow and Displaced Left-turn

The intense exponential growth of the population in the United States and added vehicles to the roads has transportation planners working on solving the congestion issue. People have to travel longer distances and spend more time on the roads causing congestion of the current networks. Thus, the demand for new roadway and intersection design is a high priority, as wasted fuel and travel time increases each year. Conventional intersection design has been in use for many years and transportation engineers know that in order to improve the current design of the intersections there are limited options. There has been a new method to solve the traffic congestion issue which is the creation of unconventional arterial intersection designs (UAID). The objective of this study is to compare the operational performance of three UAID such as the Left-turn Bypass, the Diverging Flow intersection, and the Displaced Left-turn intersection. This study will first evaluate the isolated unconventional intersection designs and then compare the intersections in a network using an existing corridor in the state of Florida. The operational performance will be evaluated based on the different results for average delay time, total number of stops, and queue time. While conducting this study the microscopic simulation platform VISSIM v. 5.10 will be used to test different scenarios. The results indicated that the Displaced Left-turn intersection operates better for almost all the scenarios described. The Displaced Left-turn consistently reports better results for average delay of less than 20 seconds per vehicle while the other two designs yield higher results values depending on the case scenario.