BACKGROUND: According to data from the National Highway Traffic Safety Administration (NHTSA), traffic crashes remain a major challenge, with 36,640 estimated U.S. fatalities in 2025 (NHTSA 2026). Pedestrians are especially at risk—a pedestrian died every 74 minutes, and a pedestrian was injured every 7 minutes in traffic crashes in 2024, on average (Traffic Safety Marketing by NHTSA). Intersections account for a significant proportion of these pedestrian fatalities, with about 18% of pedestrian fatalities having occurred at intersections in 2024 (Traffic Safety Marketing by NHTSA). In response to those concerns, and as part of the USDOT implementation of the National Roadway Safety Strategy (NRSS), the USDOT established the Intersection Safety Challenge or “the Challenge.” The Challenge was a two-stage prize competition aimed at developing new, cost-effective, real-time roadway Intersection Safety System (ISS) concepts, open to any capable and eligible entity. In the first stage of the Challenge, competitors were asked to develop concept papers describing their ISS, and the best concepts moved on to the next stage of the competition. In the second stage of the Challenge, which was open to first stage prize recipients, participating teams performed virtual testing of their ISS concepts utilizing Government-provided roadside sensor data and other supporting information. More information on the Challenge may be found at https://www.its.dot.gov/research-areas/intersection-safety/challenge, including the Challenge structure and awardees. The Challenge results indicated there is a compelling case that low-cost, infrastructure-based sensor systems, together with advanced algorithms to fuse data rapidly, show significant promise in achieving the overall vision of the Challenge. However, critical research questions remain regarding the ability of any ISS to predict and mitigate conflicts in real-time. Conflict mitigation, in particular, which is a key element of the ISS vision, requires additional research and refinement. PURPOSE: The purpose of this BAA is to build on the success of the USDOT Intersection Safety Challenge by advancing end-to-end ISS prototyping by focusing on ISS prototype development to demonstrate the physical capabilities of ISS, address key research questions regarding conflict prediction and mitigation at intersections, and consider the cost-benefit of broader ISS deployment. Note that while the Challenge was instrumental in assisting USDOT in understanding the maturity of the technologies and the risks and rewards associated with near-term ISS prototyping, this BAA is open to any eligible entity, regardless of prior Challenge participation or prizes won .