Key Insights Gained from the USDOT Connected Vehicle Pilot Deployment on Integrating CV Technologies into Deployed Transportation Systems.
Wyoming, United States
New York City, New York, United States
Tampa, Florida, United States
Advancing Interoperable Connectivity Deployment: Connected Vehicle Pilot Deployment Results and Findings
Summary Information
Connected vehicle (CV) technologies utilize advanced mobile communications to share information between transportation system users, vehicles, and infrastructure, enabling potential safety improvements and mobility enhancements. In 2015, the Intelligent Transportation Systems Joint Program Office (ITS JPO) selected three locations for the deployment and assessment of the CV Pilot Deployment (CVPD) program, including the New York City Department of Transportation (NYCDOT); the Tampa Hillsborough Expressway Authority (THEA); and the Wyoming Department of Transportation (WYDOT). The program aimed to evaluate the effects of various CV applications on safety, traffic flow, the environment, and the efficiency of public agencies. All three sites overcame several technical and non-technical challenges in integrating CV technologies into their deployed transportation systems.
- Conduct interoperability test to identify potential issues that would require resolution prior to the sites advancing to an operational phase. The three-day testing event was a major victory for the Program, successfully demonstrating cross-site over-the-air interoperability among the six participating vendors.
- Develop proactive monitoring and reporting mechanisms for security certificates and optimize firmware for efficient data management. Persistent issues with security certificate expiration and large log file sizes can hinder the normal processing of CV messages. Lessons from CVPD found that it's crucial to regularly update and optimize roadside unit (RSU) firmware to manage log file sizes effectively. Adopting strategies like pre-downloading three years' worth of security certificates or setting up weekly monitoring for certificate statuses can facilitate early problem identification and resolution.
- Ensure line-of-sight (LOS) between the antenna and receiver and supplement satellite or WiFi communication for areas with no Dedicated Short-Range Communication (DSRC) coverage. DSRC is an LOS technology, so ensuring its existence will improve transmission quality. Initial antenna placement on the cab rooftop for the Wyoming Pilot obscured trailing vehicles, so the antennae were moved onto side mirrors. In addition, WYDOT incorporated satellite communication to disseminate traveler information to areas without DSRC coverage and THEA used WiFi to overcome the challenge of communicating with pedestrians via their smartphones.
- Consider combination of techniques to improve positioning accuracy. The “urban canyon” effect in dense urban environments can impact the accuracy of Global Navigation Satellite Systems (GNSS) for CV applications. To improve the positioning accuracy, techniques such as dead reckoning, CAN bus integration for speed data, Inertial Measurement Unit (IMU) integration, and RSU time-of-flight features can be combined, as demonstrated by NYCDOT. However, these location correction services must be thoroughly tested before deployment.
- Ensure efficient, reliable, and quality installations of RSUs. The NYC Pilot originally attached their RSUs directly to the mast arm spanning the intersection, but high winds led to the signal head damaging the RSU antenna. Alternatively, the RSU was vertically mounted to reduce potential damage for signal head swing. This remounting also improved the LOS between the RSUs and the vehicles and reduced the installation time since the mounting devices were preassembled.
- Manage at scale installations and ensure durability and compatibility of equipment in varied environments. Wyoming truck antennae deployments had to handle the extreme cold and snow. NYC bus antennae had to survive car washes. Both environments presented unique challenges and required iterating through small test batches before settling on at scale installations. Additionally, conducting durability tests and discussing any modifications that alter a vehicle's original condition with the fleet owner/operator early in the process is crucial to secure approval and understanding.
