The first quarter of 2021 was the deadliest start of a year on the nation’s roads in over a decade, with car crashes killing an estimated 8,730 people from January to March, according to a new estimate from the National Highway Traffic Safety Administration.

The numbers indicate that a surge in road deaths that began with the coronavirus pandemic has continued into this year, although they offer some early glimmer of hope that unusually high fatality rates might be beginning to come down.

NHTSA said the ongoing high death rate appears to have been caused by drivers continuing to take risks by speeding, getting behind the wheel after drinking or using drugs, and not wearing seat belts. To coincide with the new estimates, NHTSA on Thursday released an updated version of a guide to improving highway safety, largely focusing on encouraging more-conscientious behavior on the roads and deterring risk-taking.

“We must address the tragic loss of life we saw on the roads in 2020 by taking a transformational and collaborative approach to safety,” said Steven Cliff, NHTSA’s acting administrator. “Everyone — including those who design, operate, build and use the road system — shares responsibility for road safety.”

The estimated 8,730 deaths represent an increase of more than 10 percent compared with the same period last year and equate to 1.26 deaths for every 100 million miles driven. That rate is substantially lower than figures for the last nine months of 2020, when the death rate climbed to almost 1.5 per 100 million miles — but NHTSA’s data shows that the beginning of the year is typically the least deadly stretch.

Asked about the decline in the fatality rate, NHTSA spokeswoman Lucia Sanchez cautioned against drawing conclusions for the rest of the year, saying figures for the second quarter of 2021 will likely be more illuminating because the effects of stay-at-home measures weren’t fully felt until April 2020.

The National Safety Council, an independent advocacy group, recently forecast that 460 people will be killed in crashes over the Labor Day weekend as people take their last trips of summer.

Experts have said the death rates in 2020 were probably in large part the result of people driving faster on roads emptied of traffic as people stayed home to avoid the coronavirus. In the initial stages of the pandemic, the overall number of road deaths declined slightly. But by summer they were surging, pushing fatality rates to levels unheard of in recent years.

Traffic volumes have rebounded, but in the first three months of 2021 Americans still drove about 7.5 percent fewer miles than they had in the same period in 2019, according to the Federal Highway Administration.

The new estimates suggest significant regional variation in the number of deaths compared with last year. In a NHTSA administrative region that stretches from Nevada northeast to North Dakota, deaths spiked 28 percent. But in the region including Maryland, Virginia and the District of Columbia, they dropped by 6 percent.

Pam Shadel Fischer, senior director of external engagement at the Governors Highway Safety Association, said state road safety agencies and police are pursuing approaches such as high-visibility enforcement of traffic laws to try to bring the death rates back down.

“But too many motorists fail to recognize their risky driving poses a threat to themselves and others,” she said. “These drivers must understand that people are dying needlessly on our roadways and they can help prevent these crashes by slowing down, stowing their cellphones, always driving sober and buckling up.”

Previous NHTSA research on the increase in fatalities during the pandemic found that the costs were not borne equally, with Black and Native American people disproportionately being killed. Experts have attributed the disparity to some communities being divided by dangerous roads and lacking good sidewalks and bike lanes.