Functional Classification MarandaObray, Transportation Planner Idaho Transportation Department
What is functional classification? • A process by which streets and highways are grouped into classes, or systems, according to the function they are intended to serve.
Why classify roads? • There are approximately 4,000,000 miles of roads in the U.S. • Some are more “important” than others • Helps determine which level of government has responsibility • Influences design • Affects how they are funded • Impacts Federal-Aid
Federally required • Functional classification is a federal requirement, however: • It is just a guide • Varies in practice by state • Functional Class boundaries are not rigid • Some states develop supplemental criteria • Don’t Over Think It!
What is the function of a road? • Provides mobility (interstate/arterials) • Provides access (locals) • Provides both (major/minor collectors)
Federal-Aid Routes • National Highway System • Principal arterials (Interstate, Other Freeways & Expressways and Other Principal Arterials) • State Highway System • Other Principal Arterials • Minor Arterials • Major Collectors
How are they determined? • Group population centers and major travel generators • Identify neighboring centers • Connect the largest directly • Connect the next group to the major centers
Interstate/Arterials • Carry most of the traffic • Primary purpose is through traffic and direct access is limited • Link cities and form an integrated network providing interstate and/or inter-county service • Examples: I-84, US-95, SH-20/26
Collectors • Major • Serve shorter more localized travel needs • Collect traffic from local streets in residential neighborhoods and channel it into the arterial system • May penetrate residential neighborhoods, distributing trips from the arterial through the area to the ultimate destination • Examples: Indiana Ave., East Powerline Rd. and Roosevelt Ave. • Minor • Provide service to traffic generators within the county that are not directly served by the higher system • Link these places with nearby cities, or with routes of higher classification • Serve more important travel corridors within the county not served by arterials • Examples: Apple Valley Rd., Homedale Rd. and Purple Sage Rd.
Local Streets • Provide direct access to homes and businesses • Designed for low traffic volumes, the collector and arterial system must be adequate, otherwise congested major streets may lead to drivers finding short cuts on local streets
Future Processes www.iplan.maps.arcgis.com/home
2025 Statewide Functional Class Map Deadlines • December 1, 2013 – All submittals due to Idaho Transportation Department Headquarters for review • February 1, 2013 – All submittals due to FHWA for pre-approval review • April 1, 2013 – All proposed changes presented to the Idaho Transportation (IT) Board • June 1, 2013 – Recommendation from IT Board • August 1, 2013 – Approval and Signature from FHWA **CONTINUOUS & COLLABORATIVE COMMUNICATION!**