How close to a train track can you set up a vegetable market?

http://www.hoax-slayer.com/train-bangkok-market.shtml

Thai vegetable market vendors pull back temporary shades and their produce off a railway track to allow a cross-country train to pass through the middle of the town of Maekrong, 60 kilometers west of Bangkok, April 5, 2001. The bustling market, in the middle of the town, has to scramble from the tracks eight times a day as trains pass, a scene repeated in other rural centers and some city slums across Thailand every day.