FOOD TRUCKS may be riding the Twitter-crazed foodie wave, but their design hasn't yet caught up. They plug along in old mail trucks and standard food carts, which are functional but boxy. They're expensive, too: A new ride from AA Cater Truck, the largest American manufacturer of food trucks, goes for $124,000 and can top $250,000 with modifications. In a quest for a true Transformers-meets-foodie marvel, we tapped owners and designers to rethink the restaurant on wheels. "It means thinking about compact spaciousness," says architect Jennifer Siegal, who taught a class on food-truck design at the University of Southern California last fall. "Making it more of a place instead of, essentially, a hole in the wall."
To keep people flocking to trucks in colder months, Thomas DeGeest, founder of New York's Wafels & Dinges, would install heat lamps . "In the winter, our business really slows down," he says.
No more trudging back to the office with lukewarm food thanks to tables and chairs , which make the truck what Siegal calls an "expandable space." One of her students, Vikki Chan, imagined a mozzarella-serving truck with slide-out tables. "The elasticity of the ingredient is reflected through the shell that allows the section to extend," Chan says.
With a display case that juts out from the truck , customers can check out their options while in line, cutting ordering time. That already works for Beverly Hills-based cupcake-truck Sprinklesmobile, says designer Andrea Lenardin. "It became clear that the display had to position itself right in the customer's space."
Lenardin dreams of a truck with photovoltaic cells on its roof . That bonus energy could make it easier to keep many appliances running at once, says Natasha Case, co-owner of ice-cream truck Coolhaus in L.A. For an extra punch of green energy, the truck's fuel would be replaced by cooking oil after it's been used to fry crispy treats.
Adjustable service window
A sliding door lengthens the service window  to make room for more servers at peak hours. "The biggest problem is really how to communicate with the customer," says Susie Loewenstein, a student in Siegal's class who designed Garden Lab, a traveling teaching garden.
Though food-truck chefs in Chicago, by law, can't actually cook in their trucks, Gaztro-Wagon's Matt Maroni says his ideal ride would have a wood-burning pizza oven . But, he says, cooking restrictions aside, "it would be tough to have a hot, open flame."
"We could have those 'Go-Go Gadget' arms with wheels to get through traffic ," says Case. Lynn Kim, one of Siegal's students, had the same idea and designed a doughnut-serving truck that straddles cars to bring treats to drivers and can also free itself from traffic jams.
A version of this article appeared in the June 2011 issue of Fast Company magazine.