Functional Classification

“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. Basic to this process is the recognition that individual roads and streets do not serve travel independently in any major way. Rather, most travel involves movement through a network of roads. It becomes necessary then to determine how this travel can be channelized within the network in a logical and efficient manner. Functional classification defines the nature of this channelization process by defining the part that any particular road or street should play in serving the flow of trips through a highway network.”  (FHWA, 1989)

CMAP’s website is a great resource for learning more about Roadway Functional Classification.

Changing Functional Classification

If a municipality wants to change their roadway’s functional classification (higher or lower hierarchy), they need to submit their request to their Planning Liaison. CMAP’s Functional Classification Revision Workbook explains the Functional Classification Revision process.

The Federal Highway Administration’s Highway Functional Classification Concepts, Criteria and Procedures 2013 edition guidelines should also be reviewed to see if the roadway meets the requirements of the proposed functional classification.

Review Process:

  1. Municipality submits their Functional Classification Revision request to the Planning Liaison.
  2. Planning Liaison places the request on the next available McHenry County Council of Mayors meeting agenda.
  3. McHenry County Council of Mayors votes to approve/deny their support of the Functional Classification Revision request via Resolution.
  4. If approved by the Council of Mayors, the Planning Liaison sends the request to IDOT for their review.
  5. If approved by IDOT, IDOT sends the request with their recommendation to Federal Highway Authority (FHWA).
  6. FHWA reviews the request and makes the final determination (approval/denial of the request) .
  7. Notification of the final decision is sent out (PL notifies municipalities).

Submit the following Functional Classification Request documents to the Planning Liaison:

  • Functional Classification Revision Request –  use Appendix A (pages 8-10 of CMAP’s workbook)
  • Marked up IDOT Functional Classification map
  • Traffic Count(s)
  • Location map (to scale & shows how the proposal connects with larger regional system)
  • Letters or Resolutions of Support from affected Municipalities/Townships

Optional documents: Traffic Projections (5 years), development approvals/Comprehensive Plan Maps, Jurisdictional Transfer Agreements/Annexation Agreements and Resolution of support from sponsoring municipality.

Additional information available on CMAP’s website: