PORTLAND, Maine — A month after regulations began allowing food trucks to operate in Portland, the city’s first licensed mobile food vendor planned to open for business Wednesday.

Love Cupcakes will sell its gourmet treats from a renovated, 1960s-vintage travel-trailer on a small, privately owned space at the corner of Center and Commercial streets.

Previously, the confectionery-on-wheels did business from the parking lot of an antiques shop on U.S. Route 1 in Falmouth.

“We just saw this little square of grass, in a great location in Portland,” said Jenny Spear, who staffs the food truck along with owners Anna and Joey Turcotte. “We got incredibly lucky.”

But not every potential mobile food vendor has been so fortunate.

The city began accepting applications for food truck licenses in mid-August, a month after it approved an ordinance regulating where and when the trucks can operate. To date, Love Cupcakes is the only vendor that has applied for a license, according to city spokeswoman Nicole Clegg.

Critics have complained the new rule is too restrictive and unfairly protects existing brick-and-mortar restaurants.

The rule confines mobile food vendors to some city parks, a few streets around the edges of downtown and industrial off-peninsula locations between the hours of 10 a.m. and 6 p.m. The rule also bans food trucks from operating within 65 feet of any working kitchen on the peninsula, and within 200 feet from other commercial kitchens.

Food trucks can operate on private property in nonresidential sections of the city during the day, and anywhere during the off-hours. But the trucks still have to keep their distance from existing restaurants.

The maze of regulation is one reason Love Cupcakes spent the summer in Falmouth.

“We bought the trailer about a year ago, and it took about a year to figure out where and how all the permits were going to work,” Anna Turcotte said.

Other potential food truck operators are still trying to navigate the maze.

Portland resident Nate Underwood said he has wanted to open a food truck for months. Stopping in Falmouth to buy a vanilla cupcake from Spear last Friday afternoon, he said, “I’m still working on [opening a food truck business], but I’ve had a heck of a time because of the size restriction.”

The city ordinance limits food trucks in public spaces to a length of 20 feet. Underwood said most of the suitable trucks he has seen for sale are former mail vehicles that measure 21 feet long.

Food trucks on privately owned lots can be up to 40 feet long, but Underwood said it’s difficult to find such spaces.

One solution is the development of large food-truck “courts” on privately owned lots. Indeed, the city rules were written with the idea of fostering these courts, said Andy Graham, who heads Creative Portland Corp. and served on the city-appointed task force that developed the rules.

Lot owners need to be “entrepreneurial,” Graham said. “It doesn’t take additional capital for a lot operator to create a food court.”

But he said the rules are “balanced too heavily on what ‘is’ … and fail to create enough reason for food truck operators and others to take the risk of investment.”

“As a result, all the places where people are, these are where food trucks are not,” Graham said.

Underwood said he can’t understand why the city rule is “super-restrictive.”

“Food trucks are a good fit for Portland,” he said. “They’re not competition for restaurants, because they serve a different type of customer, with a different commitment of time.”

Meanwhile, Love Cupcakes is preparing to celebrate its new location with menu additions, including coffee and a selection of fall-themed cupcake flavors. Spear said she is “optimistic” about the food truck’s future.

“Portland is such a great city,” she said, “and the addition of food trucks can only make it better.”