Civil aviation in Thailand is well developed. The big and medium-sized cities have airports. Bangkok’s Suvarnabhumi International Airport is a hub airport for Southeast Asia. The call letters are BKK. It is a huge airport that was opened in 2006 and replaced the older airport for Bangkok. There are budget carriers operating between surrounded countries and Bangkok and between Chinese tourist cities and Bangkok. Every week, there are flights to Bangkok from Hong Kong, Beijing, Shanghai, Guangzhou, Kunming, and Chengdu and other cities that tourists usually go to. There are direct flights to cities in the US, Europe, and Australia. The airport is about 25 kilometers (16 miles) away from Bangkok, and transportation between the airport and the city is easy.
A secondary airport for Bangkok is called the Don Mueang International Airport. Its call letters are DMK. It is mainly a domestic and military airport. It was the main airport until it was replaced by the Suvarnabhumi International Airport in 2006.
You can take a train from Bangkok to go to the major cities in Thailand. From Bangkok National Train Station, you can go to Malaysia and Singapore. However, it is a 48 hour journey to Singaporefrom Bangkok.
There are two types of bus transport options: government-run buses called BKS buses and private buses and minivans. It is recommended to avoid trouble, inconvenience and perhaps crime, avoid the "VIP" buses or minivans that are found in touristy areas and take the BKS buses. These serve the whole country. The price is a little higher, but safety and convenience seem to be worth it unless you are traveling with someone who knows about a particular private company and its service.
You can rent a car to travel, but this is a risky option unless you are used to traveling through crazy traffic that might be going on a different side of the road than you are used to. Avis, Budget, and Hertz rental offices are in the country. But be careful about scams. One scam is to charge customers for prior damage. Another scam is someone employed by the company "stealing" the car. In case of problems, there is a special emergency number for tourists who encounter problems. The number is for the "tourist police." They can often prove helpful to tourists. Their emergency number is 1155. Report theft because the lost vehicle often reappears when they get involved.
Metered taxis are common in Bangkok and Chiang Mai. But they are rare in other places. When you choose a taxi, make sure to pick one with a meter and make sure that the driver turns the meter on. A common scam is overcharging passengers.