Analytical and Empirical Evaluation of Freight Priority System in Connected Vehicle Environment

Abstract

The transit signal priority (TSP) strategy has been widely adopted as a practical approach to improving the efficiency and reliability of transit operations. Over the years, few studies have adopted the concept of TSP to implement freight signal priority (FSP) for improving the safety and operational performances of freight vehicles. Despite the promising outcome in previous studies, several drawbacks, such as inaccurate estimation of a freight’s arrival time at a stop bar and inefficient use of priority measures, have prevented their wide applications. This paper aims to develop a FSP system that utilizes emerging connected vehicle technology to overcome the challenges associated with conventional FSP systems. An estimated time of arrival (ETA)-based FSP logic was developed and analytically examined to demonstrate the operational efficiency that can be achieved. The proposed FSP system was implemented in a real-world coordinated signalized corridor for systematical analysis and validation of its field operation. Analysis results showed that the proposed FSP system can effectively address the shortcomings in traditional FSP systems by accurately estimating a freight’s arrival time and providing accurate and efficient priority measures.