The colour of the songthaew indicates its general route or usage. Most common by far are red songthaews (called rod daeng, red truck), which don't follow a specific route and roam the main streets around markets, temples, or the bus/train stations. These are the most convenient to take if you are going somewhere specific. Prices must be negotiated. but expect 20 baht anywhere within the city walls and 40-60 baht outside. Because of the city's somewhat irrational road design, especially inside the old walls, the driver may be forced to take a circuitous route to get to a nearby destination, but it will make no difference in the fare.