Memorial Day typically signals the unofficial beginning of summer. But what does summer vacation look like in the midst of a pandemic?

This time last year, more than 43 million Americans took to the roads, rails and sky, kicking off one of the busiest summer travel seasons in recent history. This year, many beaches are closed or have restrictions. State and national parks have not fully reopened. Some of the country’s biggest attractions, including Disneyland and Universal Studios, remain closed, though officials say they hope to reopen them to some degree in June.

Community pools are closed in many cities, and large events such as summer festivals, concerts, carnivals and state fairs are canceled.

For the first time in 20 years, AAA did not publish its annual travel forecast, saying only that this holiday weekend will likely be “a record low” for travel volume.

“One of the big issues this Memorial Day and also this summer is how much more unknown there is than there has been in the past,” said Michael Hunter, director of the Georgia Transportation Institute. “We kind of knew where the congestion was likely to be, kind of had a sense of travel patterns, and that’s all gone. . . . We don’t fully know what’s even allowed now.”

He added: “A lot of the draws that were causing people to travel aren’t there.”

How comfortable and able are Americans to travel, even as those attractions reopen?

The U.S. death toll from the virus appears likely to reach 100,000 by the end of May. More than 38 million Americans are unemployed. Even those who can afford to travel, experts say, may hesitate to do so despite reassurances from the industry of increased sanitation and new protocols.

Stan Caldwell, a traffic researcher and chief of Carnegie Mellon University’s Traffic21 Institute, said most Americans are likely staying at or near home this weekend and in the months ahead, noting that airplanes, trains and buses are operating well below normal levels following a plunge in demand early in the spring.

Revamping travel in those modes may be challenging because it is dependent on Americans regaining confidence in their safety.

Those who travel this summer will mostly do it by car and to regional destinations, experts say. Emptier roads and low fuel prices combined with cabin fever brought on by extended stay-at-home orders will probably drive regional and local leisure trips.

Nationwide, the average price per gallon was $1.94 on Friday. The last time the average price was under $2 a gallon leading into Memorial Day was 2003, according to AAA.

In the Washington region, the average price was $1.97 ahead of the holiday; in Virginia it was even lower than the national average at $1.70.

“Vehicle travel will be the travel of choice for summer vacation and starting this weekend,” Caldwell said. “My prediction is that there will be more regional travel by vehicle, but less overall travel in general.”

Campgrounds, hiking destinations such as Shenandoah National Park in Virginia, and beach houses or mountain cabins may be even more popular as people seek to vacation while social distancing. Traditional summer destinations known to have crowds, such as resorts or amusement parks, may not be so popular.

RV rentals and sales are up, according to RVshare, a national RV rental marketplace. The company said bookings are up 650 percent since early April, and the trend may continue as Americans who can afford a vacation look to social distancing options that allow them to travel, sleep and eat in the same place with limited contact with others.

And it’s not just rentals. Rick Miller, sales manager at Cruise America RV Rental and Sales in Manassas, said the company sold about 20 RVs this month — much quicker than expected in a regular season.

Business was slow early in the spring as states shut down, Miller said, but phones began to ring in the past two weeks as people became more fatigued of quarantining.

“We are pretty close to being sold out,” Miller said. “People are trying to go on vacation. We had 80 on the ground, and we might have two or three left.”

Airline and railroad officials said they have seen small increases in bookings in recent weeks, but the numbers remain low and industry officials are not expecting high volumes of travelers anytime soon.

John Heimlich, chief economist for the trade group Airlines for America, said in a briefing Wednesday that travelers are concerned about the risks of contracting the virus not just while flying, but while getting to and from the airport, boarding a shuttle to the rental car facility and checking in at a hotel.

Heimlich doesn’t know how long it will be before Americans regain confidence in air travel, but he predicts it will be a multiyear effort.

“People will be reluctant to travel — or even to book travel — until there is a strong degree of confidence that the health crisis and associated risks are behind us,” Heimlich said in an industry presentation.

“We see the unemployment rate climbing to 15 percent,” and while it is expected to bounce back a little bit into 2021, it is expected to stay quite high, Heimlich said. “That, of course, has implications for our business.”

After the Sept. 11, 2001, terrorist attacks, it took four years for air travel volumes to rebound, and it took seven years after the economic crisis of the late 2000s, Heimlich said. The expectation for the covid-19 crisis recovery is that family trips will resume first, followed by domestic vacationers and then international and business travel.

More than half of the fleet of U.S. airlines is grounded, idle in storage, and air travel is down more than 90 percent compared with pre-pandemic numbers. Of those planes flying, 73 percent are less than half full.

At the onset of Memorial Day weekend, 318,449 people went through U.S. airport checkpoints, about 90,000 more than the previous day, the Transportation Security Administration said. Still, the number is well below the nearly 2.7 million people screened at security checkpoints on the same day last year.

The U.S. Travel Association is projecting Americans will spend $4.2 billion this Memorial Day weekend compared with $12.3 billion in 2019. More than half of the industry’s workforce — 16 million workers in hotels, tourism, transportation and other travel branches — have been laid off.

Because many events, such as festivals, theater and concerts are canceled this summer — and because of the fears of transmission in crowds and closed spaces — the outdoors could be a greater draw this year. But even parks and beaches may be more limited as states try to maintain social distancing.

In New York, Mayor Bill de Blasio threatened to close beaches to public access if people do not follow social distancing rules. The city installed fencing at entrances that could be used if beaches — meant now only for local residents to exercise — get overcrowded or people violate swimming bans.

In Delaware, beaches reopened in time for Memorial Day, but for residents only. A mandatory 14-day quarantine for out-of-state travelers and a ban on short-term rentals remain in effect, officials said.

Popular campgrounds remain closed or are opening with restrictions or at limited capacity. In California, campgrounds at Yosemite National Park are closed as the park remains closed to the public. In Colorado, Rocky Mountain National Park is reopening in phases, and starting next week reopening or partially reopening some campgrounds.

Still, traffic data shows volumes are picking up after two months of empty streets. Researchers tracking smartphone data have found that more people from places that remain shut down are flocking to parts of the country that are reopening. Nearly 860,000 additional travelers visited parts of Maryland and Virginia that reopened last weekend, according to the data.

Those numbers are expected to keep increasing. Even this weekend, transportation officials expect more people take to the road — just not as many as in years past.

AAA says it is unlikely that low gas prices will be incentive enough for most Americans to leave home this long holiday weekend.

“Gas prices around Memorial Day have not been this cheap in nearly 20 years. However, as the country continues to practice social distancing, this year’s unofficial kickoff to summer is not going to drive the typical millions of Americans to travel,” AAA spokeswoman Jeanette Casselano said.