NEW YORK (CBSNewYork) — Brace yourself for holiday headaches if you plan on flying in or out of LaGuardia Airport next week.

The Port Authority, which operates the airport, issued a travel advisory about possible delays due to construction.

As CBS2’s Hazel Sanchez reported, travelers headed in or out of LaGuardia should be prepared for a traffic nightmare.

The multi-billion dollar plan to renovate the traffic hub will cost a lot of time.

Frequent flyer Susan Howe said it’s already taken a toll on her.

“It’s been really tough. It takes a lot longer, and is a lot less fun,” she said.

As construction crews continue to tear down some of the airports old parking garages and lots to make room for a new and improved travel experience, travelers have lost hundreds of convenient long term parking spaces.

Starting with 6,400 spaces before the project began, there will eventually be 7,200 spaces when the project is complete.

In the mean time, Sam Edwards — manager of Buccaneer Diner about a mile away from LaGuardia — said people are now trying to sneak spots in his restaurant parking lot.

“It’s very busy. I can’t afford to lose one spot. We all park outside. We all have cars here. No one allowed to park in the parking lot except the customers,” he said.

Some roadways and ramps leading to LaGuardia’s main terminal have been shut down to accomodate construction.

The backup got so bad in August, that passengers were exiting their cars on the Grand Central and walking their way in.

Port Authority Executive Director Pat Foye said the agency has taken measures to make sure everyone stays safe.

“Added police officers, police more effective than security guards,” Foye said.

Port Authority did open an 1,800 space employee parking lot to the public to accommodate spaces lost during construction.

Many travelers said they’re considering other options to avoid the mess altogether.

“Between here and Newark we don’t have a lot of choices, so I probably look at Newark more often,” one traveler said.

The new 3,000 space garage will be complete in 2018. Travelers said it can’t come soon enough.

If you need to drive and park at the airport, use long term parking lot P-10.

Nearly 350,000 people are expected to use LaGuardia during the Thanksgiving holiday, according to the Port Authority.