This paper compared the cost of a traditional emergency vehicle pre-emption (EVP) to a centralized solution implemented in San Jose.
Expanding the capabilities of your Traffic Signal Management System by centralizing emergency vehicle pre-emption management
The City of San Jose implemented a more cost-effective centralized emergency vehicle preemption (EVP) system that leveraged existing infrastructure, communications, and software systems and eliminated the need for costly field hardware installation and maintenance at intersections throughout the city.
Centralized emergency vehicle pre-emption changed the overall method of how a pre-emption request was handled in the City. The information flow was re-directed. Instead of using equipment on each emergency vehicle to communicate with intersections individually, emergency vehicles communicated with a central control system. The central system preempted signal control at individual intersections based on the GPS position of emergency vehicles and their priority as they responded to an incident.
Such a centralized emergency vehicle pre-emption system cost only $1 million, as opposed to the $9 million that would have been needed to install and maintain traditional preemption request equipment at each intersection (an $8 million cost-savings).