WHEN gourmet food trucks first appeared on America’s streets in 2008, many dismissed them as a fad. Nearly a decade later, it is clear that the trendy trucks—known for offbeat dishes, low prices and clever use of social media—are here to stay. That does not mean they are always welcome. In recent years, many cities have passed laws restricting where and when food trucks can operate. But regulating the mobile-food industry has proved difficult. How do cities keep food trucks off their streets?

The food-truck revolution is often credited to Roy Choi, who began selling $2 Korean barbecue tacos on the streets of Los Angeles in 2008. By 2015 America could boast more than 4,000 food trucks, which together were earning some $1.2bn per year. But not everyone has embraced the trend. Businesses say that their operations block streets and pedestrian traffic, take up valuable parking spaces and disrupt pavements with crowds, waste and noise. Restaurant owners complain that because mobile vendors do not have to pay rent or real-estate taxes, they enjoy unfair advantage.

Lawmakers have responded to these complaints with stricter regulation. In 2011 Boston set aside public sites where food trucks could do business—and barred them from selling elsewhere in the city. In 2013 Washington, DC passed a similar law, delimiting “zones” where food trucks could operate legally. In cities that allow food trucks to ply the public streets, truck owners typically face limits on how long they may park in a single place. In Denver vendors are given four hours per spot. In other cities, limits can be as short as 30 minutes. Some cities have gone further, imposing minimum distances between food trucks and existing bricks-and-mortar businesses. In Baltimore trucks may not set up shop within 300 feet of a restaurant. In some cities, these “buffer zones” can have a radius as large as 500 feet.

Such regulation has stifled the food-truck industry in some of America’s biggest cities. In New York, where vendors have to shell out as much as $25,000 to rent a permit on the black market (the city has not increased the number of licences in three decades), and may not park in any of the city’s 85,000 metered parking spaces, starting a food truck has become nearly impossible. In Chicago, where truck owners cannot operate within 200 feet of bricks-and-mortar restaurants and must carry GPS devices to verify their whereabouts, the food-truck market has stalled. Despite being home to more than 7,300 restaurants and 144 craft breweries, Chicago has just 70 licensed food trucks. But some are fighting the regulations: in 2011 the Institute for Justice, a libertarian law firm, successfully challenged an El Paso law that prohibited food trucks from operating within 1,000 feet of any existing restaurant. In 2015 the group won a similar case against San Antonio, which had a longstanding 300-foot rule. Where there is a wheel (or four), there is a way.