The EMTRAC system consists of three major components—vehicle components (described in this page), wayside components (commonly installed at intersections), and the software used to configure and monitor the system.
Vehicle Computer Unit (VCU)
VCU and Dual RF/Satellite-Positioning Antenna
EMTRAC-equipped vehicles carry a compact, yet rugged, Vehicle Computer Unit (VCU), which is connected to a dual RF/satellite-positioning antenna that receives precise location data and transmits priority requests to wayside equipment via secure radio. The VCU tracks vehicle location with precision, and its superior range ensures reliable reception—even in adverse conditions.
Vehicles with the EMTRAC system transmit a priority request to equipped intersections when passing through pre-defined detection zones. The wayside signal-control cabinet contains an EMTRAC Priority Detector, which relays priority requests to the signal controller.
900 MHz, frequency-hopping spread spectrum radio with secure, 256-bit AES encryption
Typical transmission range over 3,000 feet, enabling intersection-approach zones of the same length
Integrated computer board contains an ultra-fast processor and superior memory, while the MicroSD-card offers additional activity-log storage capability
Operates off nominal 10 to 40-volt DC power source with a maximum current of 500mA
Capable of communication through Ethernet, RS-232, or wireless connection
Sends four main directional codes, four auxiliary codes, while supporting up to 16 inputs and outputs in any combination
Capable of storing up to 5,000 intersection-approach zones
Ability to accept multiple inputs to prompt priority requests, including bus-door or pull-cord activity, schedule adherence, passenger count, and emergency light-bar
Time-out feature is configurable to cease transmissions after designated amount of inactivity
EMTRAC Control Head Models
The Control Head enables vehicle operators to monitor system activity and performance in real time. In addition to other features, drivers may be alerted when priority requests have timed out and when there is immediate potential for collision.
The Control Head is available in three models. The LED model (upper left) displays basic vehicle activity information. The Touchscreen model (upper right) displays both vehicle activity and specific alerts, such as collision-avoidance alarms. The Programmable model (bottom) displays vehicle activity, alerts, and may be used to change VCU configuration settings.
Indicates VCU is 1) actively receiving GPS signal, 2) the vehicle is currently in a detection zone, 3) the VCU is actively requesting signal priority, or 4) the priority request has timed out
May switch system to standby mode for monitoring/testing
Enables driver to reset timed-out priority requests
Warns driver of potential collisions with EMTRAC-equipped vehicles or personnel, as well as other designated alerts, such as if the vehicle is exceeding posted speed limits (touchscreen and programmable models)
May indicate that signal priority has been granted
Displays estimated time of arrival to defined points (touchscreen and programmable models)
Safety: Reduce collisions between equipped vehicles responding to the same emergency or on the same route by pro actively alerting drivers of potential hazards.
Efficiency: The program-capable model is equipped with a USB port, enabling agency personnel to load only intersections and detection zones for specific routes. It is also equipped with an Ethernet port, which may be used to download data or upload firmware updates.
Reliability: The touchscreen model enables drivers to reset timed-out requests to help clear intersections in even gridlock conditions.
Flexibility: The EMTRAC system may be installed on any vehicle type (first-response, buses, LRVs, snow plows, etc.), with control heads installed on only select vehicles.