27th Annual Highway Report: Urbanized Area Congestion

There is no universally accepted definition of traffic congestion. In reporting to the federal government, the states have in the past used peak-hour traffic volume-to-capacity (V/C) ratios, as calculated in the Transportation Research Board’s Highway Capacity Manual, as a congestion measure. Through 2009, the Federal Highway Administration (FHWA) summed these V/C calculations to determine the state mileage in various V/C categories. Since 2009, however, these tables have not been published by FHWA. Instead, FHWA has been reporting periodic statistics based on travel delays from mobile devices, but only for selected regions and roads, not for states. 

This year, the Annual Highway Report uses data from Texas A&M Transportation Institute’s 2021 Urban Mobility Report (UMR). This report uses 2020 congestion data. The metric selected was the “annual hours of delay per auto commuter.” UMR defines annual delay per auto commuter as “a measure of the extra travel time endured throughout the year by auto commuters who make trips during the peak period.” (The UMR data, which are computed only for urban areas, are aggregated by state. See the Appendix for details.) 

In 2020, the average annual hours of delay per auto commuter in urbanized areas was 27.04 hours (see Table 15, Annual Hours of Delay per Auto Commuter, Figure 10). Annual hours of delay range from 6.5 in Wyoming to 48 in New Jersey. The congestion problem is primarily concentrated in the major cities of just a few states. 

In 2020, commuters in six states spent fewer than 10 hours of delay sitting in peak-hour congestion. Commuters in 41 other states spent less than 40 hours of delay sitting in peak-hour congestion. Commuters in the bottom three states (New Jersey, New York, and Massachusetts) spent more than 40 hours of delay per year in traffic congestion.

Urbanized Area Traffic Congestion — Annual Peak Hours Spent in Congestion Per Commuter