SAE J2945/4_202305

This SAE Standard specifies message set requirements for roadside safety applications, including detailed systems engineering documentation (needs and requirements mapped to appropriate data exchanges). The applications include: Curve speed warning (CSW) Reduced speed zone warning (RSZW) Lane closure warning (LCW) Dynamic traveler information (DTI) Incident information (INC) This document defines a new road safety message (RSM) and the use of infrastructure-to-vehicle communications capabilities defined in other standards, including SAE Standards, and the National ITS Architecture. This does not define a single, generic, broadcast application for infrastructure systems, but a message set and structures to support the above listed applications. The new message and its structure enable additional applications to add new material to the common framework that is defined herein. This allows further development and deployment of new applications with new message content in the future. The purpose of this document is to enable roadside safety application interoperability using I2V communications, although its use with V2V and V2X is anticipated and not precluded. This SAE Standard defines a new structure called road safety message (RSM) based on the SAE J2735 traveler information message (TIM) to reflect the lessons learned from various deployments. The functionality of the message set is improved for message linking, content segmentation, and message forwarding within a security framework. Five use cases are also considered.