U.S. traffic deaths jumped 10.5 percent in 2021 to 42,915 — the highest number killed on American roads in a single year since 2005, according to a preliminary estimate from U.S. regulators.

The yearly increase is the highest reported since the National Highway Traffic Safety Administration (NHTSA) began using its current traffic fatality tracking system in 1975.

“We face a crisis on America’s roadways that we must address together,” said U.S. Transportation (USDOT) Secretary Pete Buttigieg.

In January, USDOT released a strategy designed to cut the soaring number of traffic deaths on American roads.

Traffic deaths surged after coronavirus lockdowns ended in 2020 as more drivers engaged in unsafe behavior like speeding and driving under the influence of drugs or alcohol.

Traffic deaths in 2020 rose 6.8 percent and up 18 percent over pre-pandemic 2019 levels.

Forty-four U.S. states and the District of Columbia all are projected to have an increase in traffic deaths.

NHTSA said the fatality rate in 2021 fell slightly to 1.33 fatalities per 100 million miles traveled, down from 1.34 million in 2020, which was the highest rate since 2007.

One factor for the big jump in 2020 was that drivers who remained on the roads engaged in riskier behavior, NHTSA said.

As U.S. roads became less crowded, some motorists perceived police were less likely to issue tickets because of COVID-19, experts say.