US DOT Policy on Regional ITS Architecture
Title 23 (Highways), Chapter I, Subchapter K, Part 940 of the United States Code of Federal Regulations (CFR), is about "Intelligent Transportation System Architecture and Standards." The Federal Highway Administration (FHWA) refers to this as 23CFR940. Federal Transit Administration (FTA) published the "National ITS Architecture Consistency Policy for Transit Projects" that has the same wording as 23CFR940. The purpose of the regulation or policy was to provide "policies and procedures for implementing section 5206(e) of the Transportation Equity Act for the 21st Century (TEA-21), Public Law 105-178, 112 Stat. 457, pertaining to conformance with the National Intelligent Transportation Systems Architecture and Standards." (from www.ecfr.gov - 23CFR940.1 Purpose)
ITS projects funded through the highway trust fund are required to conform to the National ITS Architecture and applicable standards. The intention of the regulation/policy is to foster the deployment of integrated regional ITS systems.
Because it is highly unlikely that the entire National ITS Architecture would be fully implemented by any single metropolitan area or state, the regulation requires that the National ITS Architecture be used to develop a "regional ITS architecture" that would be tailored to address the local situation and ITS investment needs. The region is defined by local participants and is based on the needs for information sharing and coordination. It can be a metropolitan area, a state, a multi-state area, or a corridor.
This guide makes frequent reference to the federal regulation requirements for regional ITS architectures, describing how the specific process steps and products relate to the regulation, usually referenced as 23CFR940. In addition to the regional ITS architecture requirements, the regulation also includes requirements for ITS Project Implementation and Project Administration, which are not addressed in detail by this document.
Further information on the Intelligent Transportation System Architecture and Standards regulation can be found at http://www.ops.fhwa.dot.gov/its_arch_imp/policy.htm. The text of the regulation itself can be found on the US government electronic Code of Federal Regulations (e-CFR) website on or FHWA's and FTA's websites. See https://ops.fhwa.dot.gov/its_arch_imp/archrule_final_1.htm for highways and https://www.transit.dot.gov/research-innovation/national-its-architecture-consistency-policy-transit-projects for transit.