The Deployment of the Enhanced Transit Safety Retrofit Package in the Greater Cleveland Area Evaluated the Impact of the Technology on the Reduction of Pedestrian Collisions with Transit Buses.
Federal Transit Administration (FTA) developed an enhanced version of the Transit Safety Retrofit Package (TRP) system that was originally part of the United States Department of Transportation (USDOT) Safety Pilot Model Deployment, a large-scale Connected Vehicle (CV) deployment. The enhanced TRP (E-TRP) was based on the earlier system, focusing on reducing pedestrian and vehicle conflicts with transit buses in the greater Cleveland, Ohio, metropolitan area.
Key technologies included Dedicated Short-Range Communications (DSRC) for vehicle-to-vehicle and vehicle-to-infrastructure communication, High-precision Global Navigation Satellite System (GNSS) for vehicle tracking, and Forward Looking Infrared (FLIR) cameras for enhanced pedestrian detection.
The deployment included two subsystems: (i) In-Vehicle Subsystem (IVS), a transit vehicle-based subsystem, and (ii) a Roadside Subsystem (RS) at each of the selected street intersections. The E-TRP featured enhanced versions of the Pedestrian in Crossing Warning (PCW) and Vehicle Turning Right in Front of Bus Warning (VTRW) CV applications.
The buses operated in revenue service for a period of six months, from February to August in 2018. During the first month, the IVS was put into “cloaked” mode (i.e., the system did not display alerts to drivers). The data for those concealed alerts and the drivers’ reaction time towards engaging the brakes without knowledge of the alerts were recorded. In the remaining five months, the system was taken out of cloaked mode, and the drivers received live alerts when traversing through the equipped sites.
- Consider developing a custom hardware product to fit specific needed parameters. A custom ruggedized automotive grade computer was developed for the study by a third-party contractor to incorporate the on-board unit, dedicated short-range communication (DSRC) radio, ethernet switch, and data acquisition system capabilities in a single enclosure that was reasonable in size to be installed in a transit vehicle. It was found that there were many challenges with using existing hardware on the market, such as requiring a large amount of space to house the units, copious amounts of cable, difficulty in troubleshooting issues, highly complex maintenance procedures, and lack of an ability for remote modeling.
- Install prototypes ahead of time to understand unique nuances of each make and model of vehicle in the transportation fleet. Installation of a prototype was performed on four different models of buses, involving 26 cables and numerous other hardware. Each bus model required different cable lengths and hardware locations to work correctly. This activity lowered production and installation risks and allowed for earlier finalization of the final product design.
- Use a local “live” intersection for testing prior to deployment. The City of Cleveland retrofitted an existing intersection with a fully operational pedestrian detection system, DSRC radio communication, and SPaT / MAP messaging. This activity allowed the initial phases of integration and verification testing to be performed earlier in the development process, lessening risks associated with integrating the product in the field.
- Perform Electromagnetic Interference (EMI)/ Electromagnetic Compatibility (EMC) testing. While expensive, performing EMI/EMC testing was found to be crucial in discovering flaws in this study. Testing helped improve the overall design and performance of the hardware and pinpointed its limitations.
- Understand regulations associated with deploying broadcasting DSRC radios at the roadside from the Federal Communications Commission (FCC). To get a site ready for deployment, a license from the FCC was necessary. The FCC licensing process involved getting individual licenses for each intersection location so that installation and deployment could begin. The application process, while not overly difficult, required several discussions with FCC representatives to verify terminology and expectations. Processing and approval of the application took approximately four weeks, on average, and was the greatest hurdle to the FCC licensing process.
- Establish good relationships with stakeholders involved in the deployment of the E-TRP system. The E-TRP system was successfully deployed and operated thanks to extensive collaborations efforts between involved agencies, including regional transit authorities, research entities, transit vehicles and staff providers, regional electricity power providers at the deployment sites, and the city. Without all stakeholders buy-in, deployment of the E-TRP would not be possible.