J2945/10 Recommended Practices for MAP/SPaT Message Development
This effort will be a recommend best practices document outlining how to use the current MAP and SPAT message content found in the recently published J2735. It’s primary content will deal with better explaining and demonstrating by small working examples of how suitable messages are constructed and used to meet operational needs of user. [The SAE J2735 document, being a data dictionary and not a guide, allowed only a briefs summary of this sort of material.] The intended audience for this effort are those developing new deployment using these messages in connection with intersection safety applications. This will be a recommend practice, not a standard.
Rationale: Multiple deployments, committee members, and new users are requesting additional information regarding how to develop suitable geographical lanes descriptions and intersection maps ad deployment continues, Further questions then arise regarding how to then correctly connect the signal and timing phase information from a signal controller, speaking with an NTCIP messages protocol, to SAE SPAT message formats. Existing practices, at times thought to be best practices, will be laid out. While the fundamental uses cases are more or less understood by the community of practitioners, the mechanical details regarding of how to use the messages remains to be addressed in this work.