The ITS Architecture for Canada is a presentation of functional and physical ITS elements and how they are integrated. Transportation agencies in a particular region or area should use the ITS Architecture for Canada as a framework, a common vocabulary and a guide to develop an architecture that is tailored toward the unique features of the particular region. This “Regional Architecture” is a road map of the information flow between the various systems that are essential to the stakeholders of the region. It maps out how the various ITS components are ultimately tied together and integrated, both physically as well as institutionally. Consultation with and the support by regional stakeholders are very important in the successful development and implementation of a regional architecture. In this context, stakeholders can be described as owners or operators of the existing and planned systems, parties that collect and disseminate the information as well as parties that use the information. To a large extent they are “terminators” which are described in the ITS Architecture for Canada as “representing the people, systems, and general environment that interface to ITS”. Stakeholders already deliver their activities within the prescribed polices of that region. Policies, particularly in the area of transportation, are guiding statements by which specific initiatives are undertaken. It makes sense then, that a regional architecture also reflects the policies of that region. Many jurisdictions have developed ITS strategic plans that discuss efforts to develop and expand ITS initiatives in support of transportation Master Plans. Although the ITS Architecture for Canada was first launched in 1999, “ITS Strategies” that have been developed since 1999, reference the ITS Architecture for Canada, but do not describe a regional architecture. In some cases the regional architecture is developed after the strategic plan and in other cases only the reference is made to the ITS Architecture for Canada, but a regional architecture is not developed. The question is “Where does the regional architecture fit within the policy and planning process?” This paper will discuss the development of regional ITS architectures that represent stakeholders’ interests and meet the objectives of a transportation master plan. It presents a discussion of regional ITS architectures being developed as part of the strategic transportation planning process and conclude with the statement that the regional architecture, combined with prioritization, costing, and programming of future ITS initiatives into the short, medium and long term, is the ITS Strategic Plan.