Automatic Vehicle Location (AVL) for Transit

With EMTRAC AVL (automatic vehicle location), equipped buses automatically transmit location and activity data to network-connected EMTRAC detectors in wayside cabinets. This data is displayed on central workstation monitors, showing vehicle movement on a map in real-time. It is also recorded in detailed logs for later review.

The vehicle and wayside components used for this system are the same as those used for basic EMTRAC EVP/TSP functionality, making it both a simple and cost-effective way to implement an accurate and reliable AVL system.

EMTRAC Central Monitor Displaying AVL Maps

ALV Features

  • Automatically locate specific buses and intersections with the click of a mouse.
  • Connect to intersection controller switches to enable display of current signal status on map.
  • Automatically download and save activity logs from onboard VCUs while vehicles are parked at garages.
  • Configure system to automatically generate reports, which are automatically emailed and archived at specified intervals.
  • Automatically alert designated personnel—as specified events occur or on a daily/weekly basis.
  • Verify proper system functionality by monitoring signal-controller responses to priority requests.
  • View logs and generate reports that show changes in connectivity status to help identify possible network issues.

ALV Benefits

  • Timeliness: Improve schedule adherence and maintain headway by requesting signal priority when agency-specified conditions are met.
  • Ease of Installation: Central Monitoring System interfaces with existing EMTRAC TSP and EVP system components, requiring minimal additional equipment.
  • Expandability: Agencies can upgrade their existing EMTRAC systems with minimal effort, expanding the system as schedules and budgets allow.
  • Flexibility: Customize detection zones for specific vehicle classes, and define the conditions under which TSP requests are transmitted.
  • Accuracy: The EMTRAC system utilizes precision satellite and inertial positioning to ensure exact vehicle location reporting—even in unfavorable urban environments.
  • Security: Frequency-Hopping Spread Spectrum radio signal has superior range and utilizes AES encryption.


EMTRAC System video demonstrations of EMTRAC System capabilities, including Emergency Vehicle Preemption (EVP), Transit Signal Priority (TSP), transit rail safety, vehicle detection, and signal management.

Intelligent Signal Management  -  1:13