Gourmet food trucks are a business uniquely suited to our times. A global financial crisis has made credit tight for the past several years but left the skills and ingenuity of American workers intact. An obvious response to this: business plans that can be executed with a minimum of up-front capital—a van, not the whole restaurant.

But selling food out of carts has always presented a problem. In principle, mobility ought to be a business advantage, but it’s hard to sell food unless people know where you’re going to be. Twitter, which lets you follow your favorite trucks so they can inform you when they’ll be in your neighborhood, is the ideal solution. So it’s not surprising that upscale trucks have been booming recently, earning plaudits and even their own Food Network show.

The result is a win for entrepreneurs, but a headache for incumbent restaurateurs. There are only so many meals in the day, so proprietors of fixed-location food service establishments worry that every lobster roll that’s handed over from a truck is $18 lost from their own kitchen. In an ideal world, this would trigger a frenzy of competition, as restaurants with walls and chairs scramble to prove that they’re offering a premium service in exchange for their higher fixed costs. In reality, it has sparked a frenzy of lobbying.

In California, for example, Assemblyman Bill Monning has introduced a bill that would ban food trucks from operating within 1,500 feet of a school—roughly a three-block radius.

Ostensibly Monning’s policy goal is to dissuade kids from eating at food trucks rather than at their school cafeteria. Curiously, however, his rule applies exclusively to trucks and not to, say, Burger King. What threat pizza poses to children when served from a truck rather than from behind a counter is difficult for me to say. By contrast, the peril to existing restaurants from a sudden proliferation of nimble, low-cost trucks is clear. San Francisco Supervisor Scott Weiner told the San Francisco Weekly that, as written, the rule would ban trucks from the majority of the city. It would be nice to write this off as perhaps just another instance of America’s spasmodic overprotection of children, but it’s difficult to avoid the conclusion that the people really being protected here are the restaurant owners. After all, elementary schools generally don’t even let kids leave the school building for lunch at all. Banning trucks from operating nearby looks a lot like a pretext to shut them down.

A recent report on street vending for the Institute of Justice emphasizes that many anti-truck politicians don’t even bother with Monning’s pretext. An existing provision of the San Francisco municipal code, for example, states that any business may comment on an application for a new vending license and directs the city to “consider” whether the proposed operation is located within 300 feet of a business that sells the same type of food or merchandise. It would be as if Slate were allowed to complain that it should be illegal to launch a new website to compete with our offerings, and that government should take our complaint seriously.

San Francisco’s rule affects only the same kind of food, so if you’re selling pizza I can try to offer tacos. Across the bay in Oakland, a “vehicular food vendor” is enjoined from locating within 200 feet of any restaurant or deli. Chicago’s rule is like Oakland’s, while in Atlanta there’s a 1,500-foot exclusion zone in which a vendor cannot offer a similar product. These are just the most blatant forms of protectionism. San Jose’s law requiring a mobile vendor to stay at one location (or within 500 feet of that location) for no more than 15 minutes within any two hour period seems clearly designed to make truck-based businesses impractical.

It’s difficult to know precisely where the line should be drawn. The food service industry is generally heavily regulated for safety purposes, and trucks should be no exception to that. And food sales are intimately related to parking, a fraught and much-regulated activity all its own.

But a basic rule of thumb seems to suggest itself: The fact that business owners would prefer not to face competition is not a valid regulatory purpose. A food truck is a kitchen and a vehicle and should need to follow the rules that generally apply to both things. But there’s no need for extra regulatory burdens over and above those. If you’re allowed to have a restaurant two blocks away from a school, there’s no reason to ban a food truck. If you’re allowed to park a van in a space somewhere, there’s no reason to ban parking a van that also happens to sell food.

Most of all, the fact that an existing business owner objects to the practices of a new business is a terrible reason to block a truck from operating. Space is scarce and rents are high in the centers of major American cities. If new competition can bring prices down, we’ll all be better off in the long run. Meanwhile purveyors of traditional restaurants will be challenged to deploy their unique assets—tables, chairs, a roof, walls—in ways that provide meaningful value to customers. Municipal authorities need to learn to welcome the explosion of innovation happening around them and stop trying to choke it off.