A Simulation Study of an Urban Corridor Demonstrated That a Green Light Optimal Speed Advisory System (GLOSA) Can Reduce Travel Time by About Five Percent and Stop Time by Roughly 13 Percent.
Researchers Evaluated the Effectiveness of a Cooperative Intelligent Speed Control System in Trento, Italy.
Trento
An Integrated Simulation Environment to test the effectiveness of GLOSA services under different working conditions
Summary Information
The Green Light Optimal Speed Advisory (GLOSA) system is a Cooperative Intelligent Transportation System (C-ITS) designed to help improve fuel efficiency and reduce travel time by providing an optimal speed profile, allowing vehicles to minimize unnecessary stops at intersections based on Traffic Light Signal (TLS) information. This study proposes an enhanced approach for testing GLOSA services using an integrated simulation model, ensuring a realistic representation of both the traffic and vehicle dynamics. To validate this approach, a controlled vehicle equipped with the GLOSA system was simulated traveling along a single route, approximately three-quarters of a mile long, through a city center modeled after Trento, Italy, including six TLSs. The evaluation focused on measures related to mobility and efficiency.
METHODOLOGY
The GLOSA algorithm proposed in this study minimizes travel time spent at each TLS-controlled segment by computing a reference speed which avoids unnecessary stops and reduces stop and go phenomena. When in the communication range of a TLS, the GLOSS-equipped vehicle receives the Signal Phase and Timing (SPaT) and map data messages and, on the basis of both the latter and its own position, the algorithm checks whether or not the next TLS on the vehicle’s path is relevant. Then, given the actual speed and acceleration, the algorithm computes the time required to reach the TLS. To test the validity of the proposed algorithm, 2,400 simulation runs were conducted.
FINDINGS
- Results showed that the GLOSA system reduced fuel consumption by approximately five percent.
- Results also revealed that the GLOSA system allows statistically significant reductions of about five percent and 13 percent in travel time and stop time, respectively.
