Atlanta's new trams: All aboard! A TINY scarlet hut on Auburn Avenue in Atlanta, Thelma's Kitchen and Rib Shack, serves up world-beating catfish and grits. Demand for its grub is about to soar. The reasons why sit under a nearby bridge: four shiny new streetcars, each 80 feet (24 metres) long and capable of carrying 200 passengers, waiting for the opening, any day now, of Atlanta's tram system. The 2.7-mile (4.3km) route will bring new commuters, customers and visitors to the district, and to Thelma's. The area has already attracted $370m in investment since 2010. Americans are slowly warming to public transport, and used it for a record 10.7 billion trips last year. Even those living in the South and south-west - home to some of the country's most sprawling cities - are getting more of a taste for it. In Tucson, Arizona, Orlando, Florida and Dallas, Texas, light-rail systems have been expanded recently, according to Art Guzzetti, a vice-president of the American Public Transport Association. He reckons transport links in Charlotte, North Carolina are among the best in the country. In Atlanta, the social benefits could be considerable. It is one of America's worst cities for upward mobility. A child born into a family with an income in the bottom fifth has just a 4.5% chance of making it into the top fifth; a baby born in San Francisco has a 12.2% chance. Many poor families are stuck, unable to get good jobs, partly because of the lack of public transport. The new streetcar should help by connecting residents to the city's main MARTA transport system. For some, it could also save a fortune in petrol: the average driver wastes $1,000-worth of fuel a year sitting in Atlanta's traffic. Not all southerners are on board, of course. In 2010 campaigners chanting "No tax for tracks" scuppered plans for a light-rail project in Tampa, and Rick Scott, who became Florida's governor soon afterwards, rejected $2.4 billion in federal money for a high-speed railway line connecting Tampa and Orlando. But now a private company intends to open All Aboard Florida, a passenger-rail project between Miami and Orlando; parts of the line will welcome travellers by the end of 2016. The Texas Central Railway wants to build a high-speed line too, with trains travelling at up to 205mph, to link Dallas and Houston by 2021. Demographic trends make public-transport projects increasingly attractive to private firms. Millennials (those born since the 1980s) drive far less than previous generations: only 67% of Americans aged 16-24 have a driving licence, the lowest figure for 50 years. Cheap tickets for buses and trains appeal to them. And the Atlanta streetcar will go one better: trips will be free for its first three months.