Adherence to a Common Message Standard Is Essential to Ensure Seamless Data Exchange Between Vehicle-to-Everything (V2X) Systems Within the Wider V2X Ecosystem.
Experience from Field Testing of Artificial Intelligence (AI)-Enhanced Dual-Pathway Communications in Indianapolis, Indiana.
Indianapolis, Indiana, United States
RampCast Phase II: Connected Vehicles Traffic Management Application on Indiana Highways
Summary Information
Connected vehicle systems can improve traffic operations by delivering timely, location-specific roadway information directly to drivers. To ensure seamless and effective communication among diverse platforms, this project developed an AI-enhanced traffic management system designed to deliver real-time safety and traveler information to vehicles using different communication technologies. The system uses two complementary communication interfaces: a short-range C-V2X direct interface (PC5) and a long-range smartphone-based cellular interface (Uu). An AI-based message prioritization layer uses large language model (LLM) agents to dynamically adjust both the location at which safety messages are displayed, and the order in which messages are presented based on event severity and real-time driving context. The system was tested as a research prototype on Interstate 65 (I-65) and Interstate 70 (I-70) ramp interchanges in Indianapolis, Indiana, progressing from controlled static environments in a parking lot, to surrounding streets near Purdue University’s campus, and then to dynamic highway conditions.
- Adherence to a common message standard is essential to ensure seamless data exchange between V2X systems within the wider V2X ecosystem. This project converted Indiana DOT 511 data into SAE J2735- and J2945-compliant Traveler Information Messages and Road Safety Messages. This allowed the same information to be processed by physical RSUs and virtual roadside units and delivered through both PC5 and Uu communications channels. It is useful to require standard message formats and multi-vendor interoperability testing.
- Consider hybrid communication architecture to provide more robust service than one communication mode alone. Direct C-V2X PC5 mode supports low-latency, time-critical communication, while mobile network-based cellular Uu mode provides broader and more reliable coverage under non-line-of-sight conditions. Considering hybrid communication in V2X system design can improve robustness of service.
- RSU placement should account for physical obstructions. Overpasses, buildings, foliage, distance, and other obstructions can substantially degrade PC5 Packet Delivery Radios, even when latency statistics remain low. Site and radio-frequency surveys, line-of-sight assessment, and testing of candidate antenna heights and locations should be conducted before installation.
- Test system progressively from controlled to real-world conditions. Phased testing across different distances, speeds, traffic levels, transmission rates, and obstruction conditions can help establish baseline performance and identify reliability issues across varying operational and environmental conditions.
