1-5 National Highway System Pavement Condition
percent of NHS facility miles
Note: Pavement condition is measured by the International Roughness Index (IRI) which takes a longitudinal profile of pavement roughness based on one-way facility centerline miles.
Source: U.S. Department of Transportation, Federal Highway Administration, Highway Statistics, table HM-47, available at https://www.fhwa.dot.gov/policyinformation/statistics.cfm as of October 2016.