SAE J2945/A_202404

This report specifies the minimum requirements for the Road Geometry and Attributes (RGA) data set (DS) to support road geometry related motor vehicle safety applications. Contained in this report are a concept of operations, requirements, and design, developed using a detailed systems engineering process. Utilizing the requirements, the RGA DS is defined, which includes the DS Abstract Syntax Notation One (ASN.1) format, data frames, and data element definitions. The requirements are intended to enable the exchange of the messages and their DS information to provide the desired interoperability and data integrity to support the applications considered within this report, as well as other applications which may be able to utilize the DS information. System requirements beyond this are outside the scope of this report. Earlier Vehicle-to-Infrastructure (V2I) road mapping information definitions provided in the SAE J2735 MAP message data set (DS) were tailored toward specific road geometry configurations (i.e., intersections and road segments) with the corresponding road attributes associated with them nested within each geometric definition. As such, it is not always possible to apply the available MAP definitions to other road geometries or to easily apply new attribute definitions that may be identified. In addition, size constraints were placed on the message DS, which makes it difficult to develop maps for complex or large distance road geometries. This report defines a new road geometry and attributes (RGA) data set to address these limitations.