Currently the Basic Safety Message (BSM) used by heavy truck tractor-trailers was developed for Vehicle-toVehicle (V2V) communications in the U.S. DOT Safety Pilot and uses a simplified bounding box algorithm for conveying the position and heading of the tractor-trailer. However, because of the articulated behavior inherent in a tractor-trailer, this approach does not accurately identify the trailer position or vehicle space for V2V safety applications in all situations. Consequently, in certain situations this can lead to an unacceptable number of false and missed warnings to drivers in surrounding connected vehicles. The U.S. DOT, in partnership with the Crash Avoidance Metrics Partnership (CAMP) and Mercedes-Benz Research & Development North America, Inc. (MBRDNA) conducted a project, Tractor-Trailer Basic Safety Message Development (TT-BSM), to develop technical solutions to this location identification problem for heavy truck tractors with one or more articulated trailers. TT-BSM developed several BSM enhancement approaches to more accurately represent tractor-trailer articulation. Furthermore, the team also completed the system and performance requirements and an assessment of the enhanced BSM impact on internal vehicle platform (OnBoard Equipment, OBE, necessary vehicle sensors on the tractor and the trailer) and external systems (e.g. communications channel loading, other OBE-equipped vehicles, and backend systems). The enhanced BSM can more accurately transmit position and heading for articulated tractor-trailers and thus allows for better safety warnings and fewer false and missed warnings to drivers.