Taxis in Bangkok are fixed with a meter and have a sign "TAXI-METER" on the roof. The minimum fare is 35 baht for a distance of no more than 2 km. Then the rates are 4.50 baht per km for the next 10 km, 5 baht per km for 13 to 20 km and 5.50 baht per km for any distance over 20 km There is a surcharge of 1.25 baht per minute for traffic congestion when the taxi moves no faster than 6 km/hr. The rates only apply to trips within the limits of Bangkok, which include Don Muang Airport . A toll of 40 - 60 baht for expressway or tollway must be paid by the passenger.