This article originally appeared in Travel+Leisure.

It's summer, which means road trips are in season - but this year's drives will look a little different (and no, we're not talking about the pandemic). Gas prices across much of the U.S. are rising and rental cars can be hard to find - not to mention expensive. We're in what Scott Keyes from Scott's Cheap Flights calls a "carpocalypse."

"Historically, flights were expensive and arduous for travelers [to book] and the car rental was the thing you could put off to the last minute. Now, the situation is largely reversed, where flights are cheap and plentiful and car rentals in a lot of places are unlike anything we've ever seen before," Keyes told Travel + Leisure.

Here's what happened: During the onset of the pandemic, rental car bookings dropped, leaving companies to scramble. To stay afloat, "they took hundreds and thousands of cars and sold them off on the used car market," explained Keyes. This summer, with travel - at least domestic trips - back and as busy as ever, rental car companies are trying to replenish their fleets, but the lack of vehicles is leading to increased demand and higher prices.