There is no train connection with the airport yet. Work was done on an express train connection that was ready in October 2008, a year later than planned. The train station is in the basement of the terminal (Level -1). The rail connection will connect with the Sukhumvit Line from the Skytrain in Bangkok.
Car and bus
There are several access roads, but most people get to the airport via the highway Bangkok–Chon Buri. The exit to the airport is clearly indicated. In Thailand they drive on the left side.
There are four express buses (tel: +66(0)2 622 3000) to the center of the city. A ticket costs 150 baht and buses leave from the first level. Airport Express, line 1 goes to Silom Road, line 2 to Khao San Road (backpacker area), line 3 to Central World via Sukhumvit Road and line 4 to the central train station Hua Lamphong via the Victory Monument.
Many local buses connect the airport with the city, but you must first take a shuttle bus to the Public Transportation Center. Buses from the Transport Company (tel: +66(0)2 134 4097/8) also leave from there to other destinations such as Pattaya and Nong Khai.
Car rental - Bangkok Suvarnabhumi Airport
In the Arrivals Hall there are many local and international car rental companies represented. There is a central counter for reservations. Rental cars are by the Public Transportation Center by the entrance to the airport. You can also reserve a rental car in advance using the service EasyTerra provides, they compare the rates of several providers in a single quote.
Taxis are outside the Arrivals Hall. A ride to the center of Bangkok costs approximately 300–400 baht, plus a toll fee of around 60 baht. Limousines with a driver can be reserved at the counter from AOT, Airports of Thailand (tel: +66(0)81 652 4444) in the Arrivals Hall.
In front of the terminal there is a parking garage that has two parts (A and B) for short-term parking. The area for long-term parking can be found to the left of the airport entrance. On the right side of the road to the terminal there is a large area where you may park for free.