The Tampa Hillsborough Expressway Authority (THEA) is currently installing V2X (vehicle-to-everything) equipment in its streetcars as part of its involvement in the US Department of Transportation’s (USDOT) Connected Vehicle (CV) Pilot program.
Part funded by USDOT and partly by local agencies, in Tampa, the CV Pilot project involves installing radios and computers in over 1,600 vehicles and at over 40 fixed locations at downtown intersections to enable vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication. A unique feature of the Tampa project is the installation and operation of collision warning applications in 10 of the historic electric streetcars that operate along Channelside Drive in the city’s Central Business District (CBD), where they are popular with both tourists and residents.
The streetcars run on tracks alongside city streets, obeying the same traffic signals as other vehicular traffic. Since streetcars are heavy (32-tons) vehicles, they accelerate and move slowly, and often drivers of vehicles to the left of streetcars that wish to turn right at an intersection will attempt to turn right in front of moving streetcars. Streetcars cannot stop quickly or swerve, so collisions sometimes occur. The CV Pilot application being implemented to mitigate and warn of this unsafe practice is called ‘Vehicle turning right in front of transit vehicle’.
Originally envisioned for buses, THEA is adapting the application for streetcars. Global positioning system (GPS) and dedicated short-range communications (DSRC) antennas are being installed on cars and streetcars, as well as onboard units (OBU) and display screens. The OBUs constantly broadcast and receive basic safety messages (BSM) that contain vehicles’ location, velocity and acceleration, among other values. When an OBU predicts a potential collision between a streetcar and an CV-instrumented automobile, it displays a warning on both the streetcar’s and automobile’s screens, and emits audible alert signals.
Special considerations for installing the CV equipment in streetcars include:
Each streetcar has two screens, one at each end of the streetcar, since it can travel in either direction;
Wooden panels inside the streetcars had to be removed to run cables from one end to the other and to the antennas on the rooftop;
As the streetcars have wooden rooftops, special metal plates are being added to provide proper grounding for the antennas;
The antennas are being checked carefully to ensure they can operate successfully in close proximity to the streetcars’ high-voltage (640V) power line;
Hardware and software operation are now being tested in Tampa, and the parameters of the warning algorithms are being tuned so that warnings provided to streetcar and automobile drivers give sufficient time for appropriate reactions.
To watch a video of the Tampa streetcar CV installation, click here.
