CV Pilots Take Advantage of Multiple Communication Media

The Connected Vehicle (CV) Pilot program is sponsored by the USDOT Joint Program Office for Intelligent Transportation Systems (ITS) to pioneer the deployment of connected vehicle technologies in three U.S. locations. The three locations (New York City, NY, Tampa FL, and the state of Wyoming) and their contractors are currently designing and building hardware and software to implement vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) and vehicle-to-pedestrian (V2P) communication. Trucks, buses, private automobiles, fleet vehicles and pedestrians with smart phones will all be equipped with devices to communicate with each other to provide safety-related warnings and to run applications that reduce congestion, improve pedestrian safety, and provide timely weather and work zone information.

A key goal of the CV Pilot program is to investigate best practices in field deployment of CV technologies, including communication media. While Dedicated Short Range Communication (DSRC) was required to be used for at least one application by all pilot sites, the sites were not limited only to DSRC communication. The pilot sites were encouraged to design systems that use multiple communication media to disseminate information to or collect information from drivers. Two sites, Wyoming and Tampa, have incorporated other communication media into their pilot programs.

The Wyoming CV Pilot is using a combination of communication media to transfer Traveler Information Messages (TIMs) from traffic management centers to travelers. The pilot deployment in Wyoming is over 402 miles of roadway and while WYDOT is installing 75 Roadside Units (RSUs), there are still areas with no DSRC coverage. By taking advantage of a network using both DSRC and satellite communication, equipped vehicles in Wyoming can receive TIMs in a timely manner but also actively participate in V2V and V2I applications.

All On-board units (OBUs) used in the pilot have both DSRC and Satellite capabilities. Two different vendors provide the OBUs used in the pilot. Satellite communication will enable a vehicle to receive Traveler Information Messages (TIM) when the vehicle is in the target geographic zone. This communication will support applications such that provide situational awareness warnings to the driver. While OBUs can receive Satellite messages, bi-directional DSRC messaging plays a major role in enabling V2V applications as well as communications with the RSUs for other mobility- and safety-critical applications such as forward collision warnings and distress notification. WYDOT is also using DSRC to transmit event logs back to the TMC for performance management.

One challenge to developing a pedestrian mobile application to use within a connected vehicle environment is that most smartphones are not able to use DSRC networks. To widely use the pedestrian application, the Tampa CV Pilot is using WiFi communications to interact between Roadside Units (RSUs) and the pedestrian mobile application. The Tampa CV Pilot has designed and is developing a pedestrian ecosystem centered around a connected smartphone application that can receive Signal Phase and Timing (SPaT), MAP (intersection configuration) and Basic Safety Messages (BSMs) from surrounding RSUs through WiFi to build a picture of the intersection status to enable safer crossings.

When a pedestrian has the application open on their mobile device it will automatically scan for and connect to the WiFi broadcast of the closest RSU. The RSU will send SPaT and MAP data to the pedestrian application through WiFi, which will show the current pedestrian signal status for the signalized crosswalk. The pedestrian application sends pedestrian signal phase requests back to the RSU through the WiFi network. BSMs received by the RSU are also sent to the pedestrian application which is used to calculate warnings for collisions or a transit vehicle stopping or starting within an intersection. These warnings are for research purposes only and are not displayed to the pedestrian, they are logged and sent back to the RSU for archiving.

Following the goals of the CV Pilot program, the Wyoming and Tampa sites are pioneering the deployment of CV technologies through multiple communication media. The additional communication media and use cases for Wyoming and Tampa show how CV solutions can be tailored to the specific priorities of the community.