A few years ago, you'd picture a food truck as a "diner on wheels," serving pre-wrapped sandwiches and bags of chips at a busy construction site. But that image has been flipped upside-down, from Los Angeles to the East Coast, and vendors in New Jersey are cashing in on the buzz surrounding gourmet food trucks.

Food trucks line a parking lot in Mercer County (Dino Flammia, Townsquare Media NJ)

According to Jon Hepner, head of the New Jersey Food Truck Association, the number of these gourmet vendors has spiked from less than 10 to more than 100 in just a couple years. In 2014 alone, Hepner said, there were 116 events dedicated to food trucks in the Garden State. There were four such events in 2012.

"The trucks today are focusing on one special thing and doing it better than anybody else out there, and that's where there's a real draw," he said.

The specialties run the gamut from slow-smoked barbecue to Cajun to gourmet empanadas. Hepner owns Aroy-D The Thai Elephant Food Truck, which spends most of its time in Hoboken.

These trucks, meanwhile, keep the momentum going through a heavy presence on social media. It's a business that's based more on followers than customers.

Cruising from office plaza to office plaza in Mercer County, the Surf and Turf truck offers workers a fresh, healthy alternative to workers on the go.

Surf and Turf food truck sets up shop in Mercer County (Dino Flammia, Townsquare Media NJ)

"We do lobster rolls and steak sandwiches, salmon burgers, lobster grilled cheese," said the truck's Adam Browne.

Browne said the truck is usually invited by a property management company that's looking for unique amenities to offer its tenants.

The truck has an easier time dealing with private property than public locations. In many municipalities across the state, food trucks are essentially prohibited from staying in one spot for more than 15 minutes, even if they have the proper permits.

Josh Sacks, owner of Oink and Moo BBQ in Philadelphia and New Jersey, said every time his truck enters a new town, there's a new round of paperwork to handle.

"It's just a series of getting permits and entry fees," Sacks said. "It's kind of a nightmare on that level, but it's part of the business."

According to Hepner, foods trucks are following the same rules that were written for ice cream vendors nearly 50 years ago.

"The only way to rectify this is go to city council meetings," he said. "We do need regulations that work for what it is that we provide."

For the most part, he said, police would turn a blind eye if a truck is stationary for too long, but they will crack down once there's a complaint.

Marilou Halvorsen, president of the New Jersey Restaurant and Hospitality Association, insisted food trucks should be required to follow the same standards as brick-and-mortar establishments, and that includes certification for food safety.

"We're talking about public safety here," she said, "To make sure that there is a level playing field and for consumer protection, you need to make sure that the food preparation is held to the same standard as your traditional restaurant."