The National Highway System (NHS) is a network of roads important to the nation's economy, defense, and mobility.  The NHS consists of the Interstate System, highways functionally classed as freeways and expressways, other principal arterials, roads important to national defense, plus intermodal connectors.  Intermodal connectors link intermodal terminals to the remainder of the NHS.  The NHS was developed by the US Department of Transportation in cooperation with the states, local officials, and metropolitan planning organizations, including CMAP.

A map was prepared in the fall of 2018 to reflect 2018 changes in the National Highway System. This map is posted here: National Highway System for the Chicago Region, September 2018

The NHS has gained increasing importance recently, since it is now the basis of federal highway asset management regulations and many transportation system performance measures and targets.  Some federal regulations, including design standards and billboard regulations, continue to apply to the NHS.

CMAP and IDOT collaborated on revisions to the National Highway System.  The NHS is periodically revised as conditions change.  Revisions proposed by IDOT are subject to review by Counties and the Metropolitan Planning Organization, with final approval by the Federal Highway Administration.  CMAP staff presented NHS changes to the Freight Committee and to the Transportation Committee.  Approval by the MPO Policy Committee came in June, 2018.  Final federal approval came in August, 2018.

IDOT-recommended NHS changes reflected changes in highway functional classifications in 2016. These functional classification changes, developed collaboratively with CMAP staff, were reviewed by the counties and the Councils of Mayors.  Many of the functional classification changes resulted from a close look at principal arterials, which had not been reviewed prior to their addition to the NHS by Congress as part of MAP-21, a federal authorization bill.  Most of the changes now being proposed for the mainline NHS follow directly from the 2016 changes in functional classification.

A few additional NHS changes arose in reviewing intermodal connectors and other planning activities.  CMAP and IDOT reviewed intermodal freight connectors.  Many of the changes to intermodal connectors are technical, to reconcile FHWA and IDOT records (based on prior approved changes).  Other changes are based on changes in connectivity and better information regarding truck routing.  Still more changes were based on changes and facility consolidation in the freight industry.

The Federal Highway Administration approval of the changes to the National Highway System is posted here:    Federal Highway Administration Approval of NHS Changes in the Chicago Region, August 2018

Details of NHS changes are also posted below, arranged by county.

Tabular Summary, Cook County

Council-Based Map of Proposed NHS Changes:

City of Chicago

North Shore Council of Mayors

Northwest Council of Mayors

North Central Council of Mayors

Central Council of Mayors

Southwest Council of Mayors

South Council of Mayors

Detailed Maps of Proposed NHS Changes:

Cook County

Tabular Summary, DuPage County

Council-Based Map of Proposed NHS Changes:

DuPage County

Detailed Maps of Proposed NHS Changes

DuPage County

Tabular Summary, Kane and Kendall Counties

Council-Based Map of Proposed NHS Changes:

Kane and Kendall Counties

Detailed Maps of Proposed NHS Changes:

Kane and Kendall Counties

Tabular Summary, Lake County

Council-Based Map of Proposed NHS Changes:

Lake County

Detailed Maps of Proposed NHS Changes:

Lake County

Technical changes only, not for approval:

Tabular Summary, McHenry County

Council-Based Map of Proposed NHS Changes:

McHenry County

Detailed Maps of Proposed NHS Changes:

McHenry County

Tabular Summary, Will County

Council-Based Map of Proposed NHS Changes:

Will County

Detailed Maps of Proposed NHS Changes:

Will County