Project Scope
Georgia is at the forefront in the adoption of Connected Vehicle (CV) technology, leading the nation in large scale deployment of CV Road-Side-Units (RSUs). However, the benefits of CV technology may not be achieved with the infrastructure equipment in isolation without the engagement of vehicles and drivers and presence of On-Board-Units (OBUs) capable of communicating with the RSUs. There are several CV applications that will not only improve safety and mobility directly through deployment but will also encourage involvement from the auto-manufacturers, fleet-operators, and automobile drivers in the deployment and use of OBUs in the vehicle that is essential for the benefits of CV technology to be fully realized. Emergency Vehicle Preemption (EVP) is one such CV applications that has a far-reaching potential of improving people’s quality of life.
EVP by itself is not a new technology and has previously been successfully deployed. However, the benefits of EVP has been somewhat restricted in the past, especially in congested roadway conditions, because of the line-of-sight requirement between the firetruck transmitter beacon and the preemption request receiver at the traffic signals. With CV equipment on board the emergency vehicles and CV RSUs connected to the signal controllers, the line of sight restriction is no longer required. This opens up the possibility of creating a free-flow path through the signalized intersections for the emergency vehicles. By anticipating the arrival of the emergency vehicle, based on its position as recorded by CV messages received at other RSUs in the system, vehicles on the approach of interest may be cleared before the emergency vehicle arrives at the intersection. While such a methodology has been proposed before and has seen limited implementation using GPS and cellular-phone based technologies, there is not sufficient literature on clear before-after evaluations of a distributed predictive EVP implementation. Research is also limited on the methodology of implementation. This study is targeted to fill these research gaps.
The overarching objective of this project is to provide Gwinnett County the means to improve the operation of traffic signal preemption so as to increase the safety and efficiency of emergency vehicle response time.
Specifically, the project will:- Evaluate the impact of signal preemption on delays experienced by fire response vehicles around the Peachtree Industrial Boulevard study corridor.
- Develop methodologies and algorithms for tuning parameters relevant to preemption operation across consecutive intersections, such that emergency vehicle travel time is minimized.
Current Status
Currently the research team is developing a software-in-the-loop (SIL) simulation of the Peachtree Industrial Boulevard Corridor in Gwinnett County. The SIL simulation model is driven by high-fidelity data from the field sensors and from actual signal operations at intersections in the corridor. The researchers have also gathered several hundred hours of second-by-second location data from 19 Fire Department vehicles from 6 fire stations around the study corridor. The location data help quantify the efficiency of the signal operations in reducing delays experienced by the fire trucks when they are responding to an emergency and are critical for validating the simulation results.
Scenarios are currently being developed for testing different strategies in a simulated environment as a pre-cursor to field deployment, for maximizing the delay reduction from preemption, while limiting the impact on the other traffic to a minimum.