If you are a tourist (non-resident) and want to hire a car for a few days you are able to use your home country national driving licence to drive in Thailand (with a tourist visa/exemption of visa) - ensure you carry your licence with you when driving.
For longer stays in Thailand, and if you wish to drive, you are able to apply for an International Driving Permit (IDP) in your home country. This must be carried together with your national driving licence and can be valid from a period of three months to three years. To determine if you need an IDP you should check any vehicle rental agreements and your travel insurance.
For those on a Non-Immigrant Visa (residents of Thailand), a Thai driving licence is required to legally drive a car or a motorbike. You can apply for a Thai driving licence from your local Land Transport Office in Thailand, where you should check the documentation and fees needed for application.
In Thailand vehicles drive on the left-hand side of the road.
At most intersections with traffic lights you are allowed to turn left, even if the light is red. There are usually signs to let you know if this is the case, albeit in Thai, however if you are unsure then it is best to wait for the lights to turn green, or for the car behind to let you know that you can go! Many traffic lights in Thailand have a counter indicating how many seconds remain before they change colour; you also need to pay attention to the arrows to know when to go, therefore mastering the traffic lights here can take a little practice.
General Road Markings
There is no parking allowed on red and white curb-side markings, or at yellow and white markings (although temporary pick-up/drop off, loading/unloading is permitted). Parking spaces are indicated by white squares. Large yellow X's on the road means no stopping on this area (usually at intersections).
A two-way traffic road is indicated by a yellow central line, and a white lane indicates a lane. If the line is solid it cannot be crossed, however broken lines can be crossed if safe to do so.
Pedestrian crossings are indicated by white stripes on the road, however vehicles usually ignore these.
If riding a motorcycle you should wear a helmet as this is the law (even though many locals don't). It's also advisable for your safety to wear more than shorts and flip-flops - if you come off, it's going to hurt. If you are in a car, fasten your seatbelt for safety. Whichever vehicle you are driving ensure that you have adequate insurance and your driving licence is valid. It may also be useful to note down any emergency numbers or friend's numbers in case of a problem, and if you have any medical issue to ensure these are written in Thai.
Drink driving penalties in Thailand are severe and enforced, it would be unwise to drink and drive.
Parking wherever you like is not accepted, and you may run into difficulties if you park in front of a shop or restaurant without being a customer, or take a space reserved for taxis. If in doubt ask, or find a car park.
Road rage is not advisable as many locals carry a weapon in their car, so you may find yourself in an unpleasant situation.
If you are involved in an accident, it is usually the foreigners fault (even if it wasn't), so investing in a dashcam may be a good idea. Don't cause an accident as this can quickly turn into a costly nightmare.
Being stopped by the Police
If you are stopped by the Police whilst driving a vehicle it is advisable to be polite but firm and try to assess the situation.
You will often find checkpoints on the roads, especially during holidays or long weekends. You should just lower your window and show them your driving licence and you should be allowed on your way - the police are mainly looking for drugs.
If you are stopped by a lone policeman and you didn't do anything wrong it's difficult to know if the control is official, as they are only supposed to stop you if they saw you commit an offence. You will need to negotiate in this situation, most likely with a small amount of Baht, so it is advisable to keep a few hundred Baht your vehicle and to not show you are carrying more money than you are prepared to part with!
If you are riding a motorcycle without a helmet (unadvisable), a 300 or so Baht payment should be made, with no arguments, it is against the law to not wear a helmet.
If you are fined the police may ask you to pay at the police station, however will ask you to leave something as a guarantee, such as your driving licence, which you will get back once you return with the receipt. You may be able to pay on the spot, but don't expect a receipt.