The 2021 final numbers, released Monday by the National Highway Traffic Safety Administration, confirmed earlier estimates by the agency showing a 10.5% increase in deaths over 2020. That’s the highest number since 2005 and the largest percentage increase since 1975.

Data shows a 12% rise in fatal crashes involving at least one distracted driver, with 3,522 people killed. That prompted the agency to kick off a $5 million advertising campaign in an effort to keep drivers focused on the road. Agency officials said such cases likely are under-reported by police.

The number of pedestrians killed rose 13%, and cyclist fatalities were up 2% for the year. The number of unbelted passengers killed rose 8.1%, while fatalities involving alcohol-impaired driving were up 14%.

Speeding-related deaths increased 7.9%, while crash deaths involving large trucks weighing over 10,000 pounds were up 17%.

At a news conference Monday in Seattle, NHTSA focused on distracted driving fatalities, which speakers said are entirely preventable if people stop using their cell phones, eating, or doing other things that divert attention from the road.

“Remember it only takes a moment to change your life forever,” said Sophie Shulman, NHTSA deputy administrator.

Steve Kiefer, a retired General Motors executive whose son, Mitchel, was killed in a 2016 distracted driving crash, said cell phones are a primary cause of distraction. But technology is available to prevent it including “do not disturb” modes, as well as apps and in-car systems that watch drivers to make sure they’re paying attention.

“All of this technology is available today, and there’s no reason we can’t use it and roll it out quickly,” Kiefer said.

Distracted driving deaths are related to America’s addiction to cell phones, said Kiefer, who started a foundation with the goal of ending distracted driving. He said 90% of people are aware of the danger of distracted driving, yet 80% admit to doing it. In 25 states with laws against hand-held cell phone use, traffic deaths, crashes and insurance rates have dropped, he said.

“We believe that legislation will change behavior,” Kiefer said.

Mitchel Kiefer was driving from home to Michigan State University on Interstate 96 when traffic slowed and his car was hit from behind by a driver who was distracted by her phone, Kiefer said. His car was knocked across the median and into oncoming traffic, where he was killed instantly.

The crash was not reported as involving a distracted driver, illustrating how distracted driving deaths are under-reported, Kiefer said.

Part of the increase in crash deaths is due to people driving more as the coronavirus pandemic waned. NHTSA reported that the fatality rate per 100 million vehicle miles traveled increased 2.2% to 1.37 in 2021.

NHTSA also estimates that 2.5 million people were injured in crashes during 2021, up 9.4% from 2020.

The agency said it will release preliminary 2022 traffic death data in the coming weeks. NHTSA estimates that 31,785 people were killed in crashes from January through September last year, down 0.2% from the same period of 2021.