Cars on U.S. roads are as old as they’ve ever been, potentially complicating efforts to expand the use of new safety and emissions-reduction technologies.

The age of light vehicles domestically is now 12.2 years on average, up almost two months from last year’s figure, according to S&P Global Mobility. That’s a record high and marks the fifth straight year of increases.

Analysts at the data provider pointed to the global microchip shortage, supply-chain snags and inventory challenges—all of which likely kept drivers in their old cars longer. The rising cost of new vehicles—$46,526 last month, according to Kelley Blue Book—was another deterrent for prospective buyers.

The combination could put a damper on manufacturers’ efforts to introduce newer safety technologies and to spur faster adoption of more fuel-efficient hybrid and electric vehicles.

“Everything is going to be delayed when it comes to MPGs because new vehicles are selling at a lower rate than expected,” Todd Campau, associate director of aftermarket solutions at S&P Global Mobility, said in an interview.

Carmakers sold over 15 million new cars in the U.S. in 2021, according to Cox Automotive data. EVs made up just over 3 percent of the total, with hybrids accounting for another 6.4 percent.

Campau said in addition to getting older, U.S. cars are facing more wear and tear as overall driving levels have bounced back from lows at the beginning of the COVID-19 pandemic. The group said the vehicles averaged 12,300 miles in 2021, up more than 10 percent from the prior year.

“Coupled with increasing average age, strong average vehicle miles traveled points to the potential for a notable increase in repair revenue in the coming year,” Campau said.