25th Annual Highway Report: Urbanized Area 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 traffic congestion measure.

Through 2009, the Federal Highway Administration (FHWA) summed up 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.

The past two Annual Highway Reports use data directly from the INRIX Global Traffic Scorecard. This report uses its 2019 congestion data.

The metric selected was the “peak hours  spent in congestion per auto commuter  annually.” This measure is taken directly from the INRIX Scorecard and uses real-time traffic data.

For 2019, Inrix defines “Hours Lost In Congestion as, “The total number of hours lost in congestion during peak commute periods compared to free-flow conditions.”

(The INRIX data, which are computed only for selected cities, are extended to all U.S. metropolitan areas and then rolled up by state. See the appendix for details.)

In 2019, the average annual peak hours spent in congestion in the urbanized areas across the United States was 33.43 hours.

Annual peak hours spent in congestion range from 3.40 in Idaho to 116.40 in Delaware. The congestion problem is primarily concentrated in the major cities of just a few states. Commuters in 10 states spent fewer than 10 hours sitting in peak-hour congestion in 2019. Commuters in 31 states spent fewer than 35 hours sitting in peak-hour congestion.

The bottom 19 states exceed the U.S. congestion delay average, but their totals skew the average peak hours spent in congestion upward.

Commuters in the bottom 11 states spent more than 50 hours per year in traffic congestion, with commuters in the bottom three states (Delaware, Illinois, and Massachusetts) spending over 100 hours per year in traffic congestion.

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