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Condition of U.S. Roadways by Functional System

Dataset Excel: 
Notes: 

Numbers may not add to totals due to rounding.

This edition of this table is not comparable to previous editions due to a change in the categories of road conditions.

Data is reported as the International Roughness Index (IRI) in inches per mile. Lower IRI represents smoother riding roadways. For more information on the rating system, refer to National Cooperative Highway Research Program (NCHRP) report 20-24(37)G, Technical Guidance for Deploying National Level Performance Measurements, available at http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP20-24(37)G_FR.pdf as of November 2011.

Description: 

KEY: N = data do not exist; U = data are not available.

Source: 

Rural major collector, urban minor arterial, and urban collector:

U.S. Department of Transportation, Federal Highway Administration, Highway Statistics (Washington, DC: Annual Issues), table HM-63, available at http://www.fhwa.dot.gov/policy/ohpi/hss/index.cfm as of May 5, 2016.

All other categories except rural major collector, urban minor arterial, and urban collector:

U.S. Department of Transportation, Federal Highway Administration, Highway Statistics (Washington, DC: Annual Issues), table HM-64, available at http://www.fhwa.dot.gov/policy/ohpi/hss/index.cfm as of May 5, 2016.