The INRIX Research corporation uses various data sets to track roadway conditions. Users receive guidance on how to avoid delays caused by congestion and accidents. As a result, they tend to exaggerate congestion costs in order to enhance the value of their services.  

For example, their 2018 Global Traffic Scorecard media release claims that, "Congestion Costs Each American 97 hours, $1,348 A Year," but that is not really what their report indicates, and their dollar estimate is greatly overstated. Actual average cost of congestion is much lower than they claim.

Part of the problem is that they assume that everybody ("people") is an urban-peak automobile commuter. Their analysis indicates that an average urban-peak automobile commuter spends 97 hours or about 26 daily minutes delayed by congestion. According to Bureau of Labor Statistics data in 2018 about 115 million Americans worked full time, which represents about 35% of the total U.S. population, 20% live in non-urban areas, about 10-30% of commuters use non-auto modes (lower rates in smaller cities, higher rates in larger cities), and 10-30% of employees commute off-peak or on uncongested local streets. This suggests that only 15-25% of total Americans are urban-peak auto commuters who experience significant traffic congestion delays. 

INRIX's method only measures congestion intensity, that is, the reduction in vehicle traffic speeds during peak period. It does not accurately reflect per capita congestion costs, which is the more appropriate impact to consider for planning purposes. It fails to account for commute mode share (the portion of peak-period trips made by automobile) and average automobile commute trip length, so it fails to account for the congestion avoided when commuters shift mode or live closer to their work. 

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The truth is, traffic congestion tends to maintain equilibrium: it increases to the point that some potential peak-period vehicle trips change time, mode, route or destination. Many factors affect this point of equilibrium ...