The traffic decline associated with the pandemic resulted in only half as much fuel being wasted in 2020 compared to 2019. Total excess fuel consumed due to congestion in 2020 was 1.7 billion gallons, the lowest since 1994. Before 2020, the trend was steadily rising to a peak of nearly 3.5 billion gallons in 2019. About 20% of the excess fuel in 2020 was consumed by heavy trucks.
Source: Texas A&M Transportation Institute, 2021 Urban Mobility Report, June 2021.