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Emergency Traffic Signal Override System Integration

green light - Emergency Traffic Signal Override System Integration


The DeviceMaster RTS is giving the green light to emergency vehicles in St. Louis, Missouri.The city’s Department of Public Safety created a plan to install and monitor a Traffic Signal Preemption System on selected intersections. This system allows an emergency vehicle to override the normal traffic signal operation to display a green light. The system’s goal is to allow emergency vehicles to arrive on scene quicker and to reduce the risk of accidents along the way. All components of the system must perform reliably in the harsh environment of the roadside cabinets, and to utilize the new system effectively with all the provided features, the system was required to use the existing Ethernet backbone for control and management.

Technology Solution

Brown Traffic Products, Inc. was selected by the Contractor to furnish all hardware and system integration for the system in St. Louis. Approximately 100 DeviceMaster RTS 1-Port units were installed in the project. As fire and other emergency vehicles approach a controlled intersection, the emergency vehicle sends an optical strobe signal. This signal alerts the intersection controller that the vehicle is coming and needs the right of way, and identifies the specific vehicle and its emergency priority class.

The Comtrol DeviceMaster not only reliably connects the devices to the Ethernet, the DeviceMaster’s Ethernet gateway communicates information between the street grid and central office using:

The DeviceMaster connection is used to transfer the valuable information to the central system to generate meaningful management reports.

The preemption system goes beyond a self-contained operation at each intersection. It reduces operation costs and enhances management value by connecting the Tomar Electronic Inc.’s optical preemption units to the central transportation management office via the DeviceMaster RTS Ethernet gateway. “Brown Traffic Products selected the DeviceMaster RTS 1-Port to provide serial device connectivity to the existing Ethernet backbone in the St. Louis street grid because of DeviceMaster’s versatility, reliability, ease of use, and cost effectiveness.” Candy Rivelli commented from Traffic Systems Solutions.

“Brown Traffic Products selected the Comtrol DeviceMaster because of its versatility, reliability, ease-of-use, and cost-effectiveness.”

— Candy Rivelli, Traffic Systems Solutions