You won’t have a lot of wiggle room.

Plan on being packed in like sardines on aircraft this summer, particularly if you’re in coach.

The number of flyers this summer is projected to be 3.4% greater than last summer, said Tom Spagnola, senior vice president of supplier relations for CheapOair. That may seem minuscule, but 3.4% of the 2.8 million who are expected to fly domestically each day is about 95,000 more people.

Load factors — that is, how full the plane is — topped more than 84% in 2018, according to the Bureau of Transportation Statistics. Good news if you sell airline tickets. Mitigating news for travelers: More than 110,000 seats have been added, Spagnola said.

But overall, if you need to change your seat or breathe, if you miss your connection and must rebook, if you need to speed through security or want to quickly grab food, you may be caught in a crowd.

How do you prepare for these scenarios?

Better chance at a better seat: Check in exactly 24 hours before flight time and see what’s available without charge.

Breathing: You’re on your own.

Missed connection that’s not your fault: Carry with you the airline’s customer service number so you can get an early start on finding another connection. Be charming.

Slow security: Allow more time.

Hunger: One word — snacks.

And your plane may not be as fresh as a daisy.

The grounding of the 737 Max isn’t helping, said Seth Kaplan, a transportation analyst, but proportionately, those aircraft aren’t huge parts of most fleets.

But airlines want to add capacity in their busy summer season. If they have taken 737 Maxes out of service, that means they may delay refurbishing some aircraft, Kaplan said, and rotate in older planes.

Fares may not be quite as high as feared.

Fuel prices have been up and down, although it takes a while for any fluctuation to cycle through the cost structure. The fuel cost is important, Spagnola said, because it represents about 25% of the ticket price.

Low-cost airlines keep downward pressure on those fares. The demise of Wow Air this year sent ripples through the industry, but the scope of its service was largely Iceland. Of greater concern: Norwegian Air, which serves many routes from the United States to Europe, has been on unsteady financial ground. Fingers crossed.

You can choose how uncomfortable you want to be.

The discomfort you suffer usually will reap you some savings. The words “basic economy” chill some, thrill others. That’s the fare class that’s all the rage with super-economy travelers.

Depending on the airline and its rules, in exchange for a discounted ticket, you can’t choose your seat (you most likely will be stuck in the middle), there may not be a carry-on option (so you must pay to check or fly with almost nothing), you lose your fare if you can’t go (not even a change fee will save it) and you don’t get points (maybe the least of your problems).

Sometimes you don’t get much of a discount, either. I was considering a trip to the Pacific Northwest, and my choice for one leg was basic economy or plain old economy. The flight is just long enough that I didn’t want to be squashed between two tired executives on a Friday night trip home, so I spent the $20 more for economy. When it came time to choose my seat, I realized I had outfoxed myself. It was a regional jet with two-and-two seating. No squashing there. And it’s a small plane, so I may end up gate checking my small bag.

Flying to Hawaii may be a bargain.

Besides Southwest’s entry into the market, Minnesota-based Sun Country is a seasonal player, with flights from LAX, Spagnola said.

Keep in mind that Hawaiian Airlines has said it will introduce a basic economy fare between October and end of the year. No word on the date that might happen.

Whether you’re flying or driving, taking some kind of break this summer is a good idea. We Americans still leave too many vacation days on the table and work too hard.

So see you at the airport. And for heaven’s sake, bring snacks.