Getting between cities in Thailand can be very simple. Most people take airplanes, and most tourist cities have airports. Flying in you'll probably have to transfer in Bangkok, then it will be followed by a short flight to your final destination. Flying is quick, however it's pricier than other options and you'll miss out on seeing some of the country side.
Travelling by bus and train can be much more affordable, and if you take night trains or buses you'll save a night in a hotel. The ride from Bangkok to Phuket or Chaingmai could take as much as 10 to 12 hours.
Both the buses and trains offer several class levels, the 1st and 2nd class trains and buses will offer air conditioning, beds in overnight rides, and snacks, drinks, and meals. In all cases alcohol is not permitted on the vehicles. The advantage of travelling at night is that you have a place to sleep and you'll arrive early to your destination. The disadvantage comes to anyone over 5 foot 6 (due to the size of the reclining seats on the vehicles). Daytime travel while taking more out of your travel time gives you the opportunity to see the country a little more.
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