The Federal-Aid Highway Act of 1973 required the use of functional highway classification to update and modify the Federal-aid highway systems by July 1, 1976. This legislative requirement is still effective today.
Functional classification is the process by which streets and highways are grouped into classes, or systems, according to the character of service they are intended to provide. The functional classification system recognizes that streets cannot be treated as independent systems rather they are intertwined and should be considered as a whole. Each street does have a specific purpose or function. This function can be characterized by the level of access to surrounding properties and the length of the trip on that specific roadway.
Federal Highway Administration (FHWA) classification system for urban areas is divided into urban principal arterials, minor arterial streets, collector streets, and local streets. Principal arterials include interstates, expressways, and principal arterials.
Within the urban area there are three important reasons to classify roadway, they are:
- Eligibility for federal aid;
- Recognize the regional importance of specific road within the urban area; and
- Plan for the design of operation of regionally significant facilities.
The region is served by Interstate 15 (north/South) and Interstate 86 (east/west). While classified within the arterial class they are designated at the Federal level. Interstates will be shown in the functional classification map, but they will not be specifically addressed in this report.