While hundreds of thousands of people took to Maine roads last week, traffic was down considerably, leaving uncertain how Thanksgiving travel might contribute to a post-holiday coronavirus surge.

Health officials and the U.S. Centers for Disease Control and Prevention had warned Americans to put off nonessential travel and avoid holiday gatherings as the pandemic rages out of control.

Traffic on Maine roads last week hit its lowest point since early May. The number of miles traveled by vehicles in the state was down 14 percent from the same week last year, the widest such gap in five months, the state Department of Transportation reported. The reporting period covered the entire week, not just the holiday travel period.

“In recent weeks, year-over-year decreases in statewide vehicle miles traveled have been between 5 and 10 percent. The data from the week of Thanksgiving show the biggest decrease we’ve experienced since July,” said department spokesman Paul Merrill.

Traffic on the Maine Turnpike from Wednesday to Sunday was 33 percent lower than last year, an even larger decrease than the 14 percent decline the Maine Turnpike Authority predicted.

Almost 715,000 vehicles passed through toll checkpoints over the five-day period, about 20 percent fewer than the two prior weeks. Daily transactions at the York tollbooth, the primary gateway for out-of-state travel, were 32 percent to 62 percent lower than in 2019. Those transactions include passenger and commercial vehicles, such as heavy transport trucks.

Rainy, miserable weather over the weekend, along with concerns about the virus, could have suppressed travel, said turnpike authority spokeswoman Erin Courtney.

“Bad weather significantly impacts travel on the turnpike, especially on weekends,” Courtney said. “On a Thursday or Friday, people are still commuting, but on a holiday weekend when people are off, they might decide to stay home instead of venture out if it is raining or snowing.”

Maine’s top public health official said it is too early to know what impact the apparent decrease in travel could have on a potential surge in COVID-19 cases after Thanksgiving.

“It is going to be a little while before we know if that 30 percent reduction, how we should characterize that or how we should think about it,” Dr. Nirav Shah, director of the Maine Center for Disease Control and Prevention, said at a news conference Monday.

It can take as many as 14 days after any event for transmission to be detected, Shah said, so the impact of holiday travel and gatherings may not become evident until next week.

“The proof will be in the pudding,” Shah said.

Illnesses and deaths from COVID-19 have skyrocketed in Maine since mid-October. The state reported 20 new deaths from the disease and more than 200 new cases Tuesday.

Public health experts and officials across the U.S. urged people to reconsider holiday travel and traditional family gatherings. Despite the warnings, millions decided to move around the country, potentially spreading coronavirus further as illnesses spike in nearly every state.

More than 1.2 million people passed through U.S. airports Sunday, the busiest day of air travel since the pandemic began. On the same day, Anthony Fauci, the country’s top infectious disease expert, warned of a “surge upon a surge” in the next few weeks and urged people who did travel for Thanksgiving to wear masks, keep their distance from others and avoid crowds.

In a statement, a spokeswoman for Gov. Janet Mills thanked those who took steps over the holiday to protect themselves and their fellow citizens, including those who avoided trips they would have otherwise taken. “While we may not be able to quantify the impact of their actions, it is likely that they mitigated the spread of the virus from what it could have been if they traveled and, as a result, saved lives,” said the governor’s press secretary, Lindsay Crete.

Air travel in Maine was slightly higher than previous weeks but still almost two-thirds below the same time last year, consistent with passenger counts since March.

Maine airports recorded 9,038 inbound passengers over the week, about 300 more than the week before.

The Portland International Jetport saw slightly fewer passengers last week than the week prior. Passengers counts were about 62 percent below the same time last year.

Tuesday, Wednesday and Saturday were the busiest days, when 1,200 passengers a day passed through security checkpoints.

“There was some media attention that seemed like everything was back and we were crazy. That was not the case,” said jetport Director Paul Bradbury. “Normally would would have a pickup for Thanksgiving, and we did, but it was still better than 60 percent off 2019 numbers.”

About 461 people traveled to Maine on intercity bus, about 35 more passengers than the week before. Passenger rail carried 464, about 141 more than the prior week, according to the Maine Department of Transportation.