The National ITS Architecture provides a framework for planning, programming, and implementing intelligent transportation systems. The architecture framework is comprised of two technical layers, a Transportation Layer and a Communication Layer, which must operate in the context of an Institutional Layer.
The Institutional Layer includes the institutions, policies, funding mechanisms, and processes that are required for effective implementation, operation, and maintenance of an intelligent transportation system. The Institutional Layer is shown as the base because solid institutional support and effective decisions are prerequisite to an effective ITS program. This is where the objectives and requirements for ITS are established.
The Transportation Layer is where the transportation solutions are defined in terms of the subsystems and interfaces and the underlying functionality and data definitions that are required for each transportation service. This layer is the heart of the National ITS Architecture.
The Communications Layer provides for the accurate and timely exchange of information between systems to support the transportation solutions.