IT WAS in 2008 that an out-of-work chef named Roy Choi began selling $2 Korean barbecue tacos from a roaming kitchen on wheels, tweeting to customers as he drove the streets of Los Angeles. Mr Choi’s gourmet food truck has since inspired a reality-TV programme and a hit Hollywood film, and helped jumpstart a $1.2bn industry.

Within the food industry, the food-truck business, built on unique dishes, low prices and clever use of social media, is the fastest-growing segment. Restaurants fret about an army of trucks stealing customers but such concerns are unwarranted. According to the Bureau of Labour Statistics, counties that have experienced higher growth in mobile-food services have also had quicker growth in their restaurant and catering businesses.

Although many cities have treated food trucks as a fad, a nuisance, or a threat to existing businesses, others have actively promoted them. Portland, Oregon, known for its vibrant culinary scene, has had small food carts on its streets for decades. After a study in 2008 by researchers at Portland State University concluded that the carts benefited residents, the city began encouraging the use of vacant land for food-truck clusters or “pods”. Today, Food Carts Portland, a website, reckons the city has over 500 carts and trucks.