Urban Functional Class Maps

The current electronic and printed versions of the Urban Functional Class Maps shall supercede all previous editions.

These maps depict the approved revisions to the Urban Functional Classification System in Oklahoma based on the 2010 Bureau of Census data. These revisions have been approved by the Federal Highway Administration (FHWA).

Functional classification has been an important factor in Federal-aid highway programs for many decades. A roadway functional classification system has been helpful to a variety of government agencies in areas of planning, organizing, jurisdictional responsibility and cost allocation.

Functional classification is the process by which streets and highways are grouped into classes according to the character of service they are intended to provide. Cities, towns, businesses, farms, homes, schools, recreation areas and other places generate or attract trips. These trips involves movement of vehicles through a network of roads. It becomes necessary to determine how travel movement can be channelized within a limited road network in a logical and efficient manner. Functional classification defines the nature of this channelization process by defining the role that any particular road or street should play in serving the flow of trips through a road network. The heavy travel movements are directly served by major channels, and the lesser trips are channeled into somewhat indirect paths.

The Functional Classification System is divided into rural and urban areas. The characteristics of these two areas are different in the types of land use, street and highway networks and the nature of travel patterns.These maps covers the urban and urbanized areas. The classification data for rural area roadways is known as The County Collector System. For a more detail description of the rural functional classification system, see the State’s Rural Area Functional Classification section.

The urban areas are further divided into the small urban and urbanized areas. Urban areas are urban places designated by the Bureau of Census according to the population densities. An urban place with population between 5,000 and 49,999 becomes a small urban area. Any urban place with population less than 5,000 will fall into the County Collector System. The urbanized areas are urban places with a population of 50,000 or more.

In every urban environment there exists a system of streets and highways which can be identified as unusually significant to its surrounding area in terms of the nature and composition of travel it serves. These facilities in smaller urban areas (less than 50,000) may be limited in number and extent. The importance may be primarily derived from the service provided to travel passing through the area. Larger urban areas may have the importance of service from rural oriented traffic, but equally or more important from service of major travel within urbanized areas. The following are the main characteristics for streets and highways of the urban principal arterial system.

1. Serves the major traffic movements within urbanized areas connecting central business districts, outlying residential areas, major intercity communities, and major suburban centers.
2. Serves a major portion of the trips entering and leaving the urban area, as well as the majority of the through traffic desiring to bypass the central city.
3. Provides continuity for all rural arterials which intercept the urban area.

The principal arterial system is subclassified as follow:

1. Interstate
2. Freeways and expressways (A fully or partially controlled access facility)
3. Other principal arterials (No controlled access)

The minor arterial street system includes all arterials not classified as a principal and contains facilities that place more emphasis on land access than the higher system. This system should have the following characteristics:

1. Serves trips of moderate length at a somewhat lower level of travel mobility than principal arterials.
2. Provides access to geographic areas smaller than those served by the higher system.
3. Provides intracommunity continuity but doesn’t penetrate identifiable neighborhoods.

The collector street system differs from the arterial system in that facilities on the collector system may penetrate residential neighborhoods. The characteristic of the collector street system are as follow:

1. Collects traffic from local streets in residential neighborhoods and channels it into the arterial system.
2. Provides both land access service and traffic circulation within commercial areas, industrial areas, and residential neighborhoods.

The local street system offers the lowest level of mobility and the highest of land access service. The characteristics for local street system are the following:

1. Comprises all facilities not on any of the higher systems.
2. Provides direct access to land and to higher road systems.
3. Through traffic usage is discouraged.