People started lining up outside SEI's sprawling headquarters in Oaks even before Thais Viggue and her sunflower yellow Dia Doce cupcake truck rolled onto the campus.

Dave Bell got there 15 minutes early so he could be first, because, he said, he'd seen the line "go all the way down the road." He ordered a half-dozen of the $3 treats - three Black Magic, one churro, and two key lime - for himself and some friends.

It was just a couple of years ago that a customer like Bell would have to drive all the way to West Philly's college campuses or the hipster mecca of Northern Liberties to indulge in the dining craze of the 2010s - gourmet food trucks.

But times have changed. A growing number of entrepreneurs realize that Philadelphia's suburbs, and even an exurb like Oaks, are barren deserts for trend-seeking foodies who have the hunger and the cash for delicacies like Korean tacos and gourmet pizzas.

Increasingly, you'll find these haute cuisine meals-on-wheels at suburban festivals and farmers' markets, steel-and-glass office parks and leafy college campuses - the kind of place where a visit from an ice cream truck blasting "Turkey in the Straw" used to be a rare summer treat. The newcomers bear names like Dog Bites, Sum Pig, Vernalicious, Hillbilly BBQ, PJ's Wing Truck, and the Cow and the Curd.

"Honestly, when I started, I was thinking I would be in the city a lot, but now we're hardly ever there," said George Bieber, a Pottstown restaurateur who started Sunflower Truck Stop in August.

Bieber, whose truck offers gourmet sandwiches such as Green Curry Bacon BLT, Crab and Artichoke Grilled Cheese, and Sweet Potato Quesadilla, recalled that in one town, two older permitting officials eyeballed his rig as if it had landed from Mars.

"They saw that it was not just a hot dog truck, it was something different," said Bieber, who ultimately was invited by the officials to park at the town's Community Day.

Last year, Montgomery County licensed 76 mobile food vendors.

"I would say they're growing. You see them everywhere," said health official Pam Lawn.

Every other Friday, the county invites a truck to pull up outside the courthouse in Norristown as a special treat for workers.

On her first day at SEI, Viggue, whose company name means "sweet day" in Portuguese, sold out of the 1,000 cupcakes she packs into her truck in 15 minutes. She returned the next day with twice as many and sold out again.

Maybe it was her appearance not long before as winner of the Food Network's Cupcake Wars. Viggue had only been in business six months when she appeared on the show in March. In a day that sounds anything but sweet, she and a partner beat three other contestants in a three-round contest that ended with their whipping up 1,000 cupcakes in an hour and a half.

"It was insane," said Viggue, who only uses local, sustainable ingredients, some of which she and her husband grow.

Since then, the former fashion designer, who lives in Chester Springs, has been on the road six days a week, mostly in West Chester and the Main Line, starting her day in the kitchen at 3 a.m. and ending late at night.

That the work is brutal is an understatement. Josh Goldstein, a former Four Seasons chef, left a job as a top salesman for a tomato products company to open the Pizza Wagon, a mobile pizzeria that features a $15,000, Italian-made, wood-fired oven that can turn out 120 perfectly crisp pizzas an hour.

But imagine standing by that 1,000-degree oven on a 103-degree day, as he did one day last summer in Norristown. Or spending 12 hours on a freezing pavement at Spring Mountain, where he sold pizzas on weekends last winter.

"It's the business we choose to be in, so we don't complain," said Goldstein, 35, who lives in North Wales and recently was manning the stove at Evolve IP Corporate Park in Wayne.

A steady stream of customers filed out of buildings for a $10 lunch - a good-size pizza and a drink - that was in and out of the oven in a minute and a half.

The Wagon is a big improvement over Wawa, the closest place to grab a quick lunch, workers said.

Anne Dieter, who lined up with her office mates, bought an extra Buffalo chicken pizza to bring home for her husband's birthday.

"He loves this pizza. So does my son," who is 13 months old, she said.

Though some have suggested that the food-truck trend may have peaked, the National Restaurant Association estimates mobile vendors will generate about $2.7 billion in revenue by 2017, a fourfold increase from the 2012 revenue estimate of $650 million.

The Philadelphia Mobile Food Association, which organized in May 2012, has 93 members, about 20 percent of whom work primarily in the suburbs, said Sunflower's Bieber, an officer of the group.

Since there isn't the walk-by traffic that can make or break a city-based business, suburban truck owners have to pick the best locations, which vary by town.

"You can't just park curbside and hope for the best," Beiber said.

Most communities have embraced the trend, but not all. "Lower Merion was a bit unwelcoming," he added.

Sum Pig co-owner Steve Koste, 37, who lives in Warminster, said not everyone gets his barbecue-theme truck, which hit the road on Labor Day weekend.

"It's not an everyday sight like it is in the city," he said. "We pull up, and people look at the truck and say, 'What is that, an ice-cream truck?' "