Functional classification is the grouping of highways, roads and streets by the character of service they provide and was developed for transportation planning purposes. Basic to this process is the recognition that individual routes do not serve travel independently in any major way. Rather, most travel involves movement through a network of roads. Comprehensive transportation planning, an integral part of total economic and social development, uses functional classification to determine how travel can be channelized within the network in a logical and efficient manner. Functional classification defines the part that any particular route should play in serving the flow of trips through a highway network.
FHWA Directive 23 CFR 470 states that the State transportation agency has the primary responsibility for developing and updating a statewide highway functional classification in rural and urban areas to determine functional usage of the existing roads and streets. The State transportation agency is to cooperate with responsible local officials, or appropriate Federal agency in the case of areas under Federal jurisdiction, in developing and updating the functional classification. The results of the functional classification is to be mapped and submitted to FHWA for approval and when approved serve as the official record for Federal-aid highways and the basis for designation of the National Highway System.
The Washington State Legislature in RCW 47.05.021 (pdf 36 kb) and the Federal-Aid Highway Act direct the WSDOT to analyze the entire state highway system to "subdivide", classify, and sub-classify all designated state highways according to their function and importance.
The functional classification process is a cooperative effort involving the various local agencies, WSDOT Regions, Highways and Local Programs, Metropolitan Planning Organizations, Regional Transportation Planning Organizations, Strategic Planning Office and the Federal Highway Administration. The Functional Classification Process Flowchart will outline the basic steps in the functional classification request process. Your Regional (WSDOT) Highways & Local Programs office can also assist with the process. Functional classification requests must include the standard Functional Classification Request Form (doc 74 kb).
Questions or comments regarding the Functional Classification, please email the Functional Classification Section or call (360) 570-2441.
The functional classification map accessed through the following link reflects the Federal Functional Classifications for Washington State as defined and approved by the Federal Highway Administration (FHWA). The map is updated periodically. Changes in the functional classification system may be officially approved and not yet reflected on this site. Please refer to the "Functional Classification Request Status (pdf 44kb)" document to determine whether approved requests have been included in this map.