[header] How to avoid tourist traps in thailand [title] Learn never to listen to the touts (airport or shopping). [step] They will either overcharge you or take you somewhere that gives them a commission. [title] Use taxi meters (all have lights on top of the car). 
[step] If they say the meter has broken, get another taxi. Alternatively, you could establish the price before leaving (not when you arrive) but this is unlikely to be a fair price.