Like a lot of Americans, Peter Hoagland is looking forward to a summer vacation. But when he tries to picture it, the image won’t come into focus.

“My wife and I are still not comfortable with flying and cruises,” says Hoagland, a consultant from Warrenton, Va. “International trips seem too iffy. I’d hate to wind up on a cruise in Europe and have an outbreak of a covid-19 variant.”

No one knows what will happen this summer when it comes to travel. But that hasn’t stopped experts from trying to guess.

Like last summer, they say, people will stay closer to home, travel in the United States and avoid crowds. The difference: Prices will be much higher.

Travelers like Hoagland are playing it safe. He and his wife plan to drive to the Carolinas in May. They’re also planning a long car trip to New England in July.

“Some of our stops will be with vaccinated family and friends,” he says. “The other stops will be at lodging where they, too, take covid-19 seriously.”

He can expect to pay more, because prices are rising. Average rates for hotel rooms in June, July and August are soaring. RateGain says the average hotel rates have spiked to as high as $275 a night, an increase of 75 percent compared with the last two summers. And booking volume is roughly double that for last summer. RateGain tracks hotel prices from a network of branded hotels, including high-end resort properties and business-travel hotels.

“I expect domestic travel activity in the U.S. to continue to improve with the vaccination rollout,” says Chinmai Sharma, president of RateGain.

Airfares remain about 10 percent below 2019 summer levels, according to Priceline. The real “gotcha” this summer will be rental cars. The big brands cut their fleets so aggressively because of the pandemic that they ran out of vehicles in some markets.

“On average, daily rentals are up over 30 percent versus 2019 levels, with sticker shock pricing frequently found at major summer destinations,” says Brett Keller, CEO of Priceline. “Book early to avoid sellout situations.”

Another summer wild card: vaccine passports. These IDs, which use smartphone apps to verify vaccination status or negative coronavirus test results, are still under development. Several cruise lines have announced that they will require passengers to be vaccinated, and some people are worried that the travel industry might begin segregating customers based on vaccination status.

“Right now, there are a lot of unknowns over vaccination passports and proof of vaccinations as a possible entry requirement,” says Anna Gladman, CEO of World Nomads, a travel insurance company.

When will we know more? The European Union is expected to introduce a vaccine passport, called a Digital Green Certificate, by June. There are competing passport offerings in the United States, says Michael McCormick, CEO of Travel Again, a travel industry coalition dedicated to a post-pandemic recovery. But there is no timeline for the adoption of standards.

“Although the [Centers for Disease Control and Prevention] has given new guidance that vaccinated individuals are safe to travel, our work is not done,” McCormick adds. “Now it is essential that we build on this success by continuing to work together to fully and safely reopen both domestic and international travel. The speed and success of our recovery depend on it.”

But when will governments lift their quarantines? A lot depends on the trajectory of infections, but we have a little clarity on that question. Greek tourism officials expect to be open for business by mid-May, according to Ioanna Dretta, CEO of the nonprofit Marketing Greece. She says officials expect the E.U.’s Digital Green Certificate to be operational by June.

“Provided that the Digital Green Certificate system covers all different types of covid-19 certificates — vaccination certificate, test certificate and certificate of recovery — no quarantines will apply to those bearing the certificate,” Dretta says.

It remains unclear how U.S. citizens can avoid a quarantine. But Stephanos Chaillou, an analyst for A2 Global Risk, a risk management company, says the type of vaccine a traveler has received will matter.

“Only vaccines approved by the European Medicines Agency will be recognized,” Chaillou says. As of now, there are four: BioNTech-Pfizer, Moderna, AstraZeneca and Janssen Pharmaceutica NV. So if you have received anything else, you probably can’t get a vaccination passport.

Should travelers feel confident about booking a trip now? Yes, but not entirely.

“Travel sentiment is rising to a healthy level of confidence,” says Craig Zapatka, co-founder of Elsewhere, a travel site. “Bookings are already happening for places travelers think might reopen.”

But Zapatka says travelers still must be careful. He advises taking all the steps recommended at the start of the pandemic. These include masking up, using hand sanitizer, avoiding large crowds and buying enough travel insurance. And get vaccinated if you can.

Experts say you shouldn’t assume that travel will be safe, even if you take all the right precautions. That’s because no one knows what will happen.

“You should study websites and make sure a tour operator or outfitter is still addressing covid-19,” says Peter Grubb, founder of ROW Adventures, an active outdoor travel company based in Coeur d’Alene, Idaho. “If the company has a plan in place, you should feel confident.”

That advice extends to a variety of types of travel, notably cruising. Look for an insurance policy that addresses safety precautions, cancellations and trip credits in case of another outbreak. If you have questions, ask your travel adviser or the vendor in question to clarify. And if you don’t like the answer, don’t book.

It’s going to be an interesting summer. Be careful out there.

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