Functional classification is the process required by the Federal Highway Administration, which divides the nation's network of streets into categories according to the function provided. It represents the function of a roadway based on several factors, including the volume of traffic, access to adjacent properties, length of the specific segment, and speed of the roadway.

Functional classification is used in transportation planning, roadway design and the allocation of federal roadway improvement funds. It was introduced by the Federal Highway Administration in the late 1960s, which developed federal guidelines for local governments and planning organizations to use in maintaining the functional classification system in their own jurisdictions.

BTPO and local government agencies review the federal functional classification system every ten years. The review evaluates the function and characteristics of all public roads to determine the classification. Streets that are classified as Major Collector, Minor Arterial, Principal Aterial, or Interstate are eligible for federal funding.

2010 Functional Classification Map was approved in 2012 and is the official Federal Functional Classification Map for the BTPO Planning Area.