International Driver's Permit (IDP)

To drive either a motorbike or a car, the driver must be able to produce a current International Driving Permit (IDP) in addition to a current national driving license. There is an on-the-spot fine of 400 Baht if the driver is unable to show an IDP.

An IDP is so you can drive in any country (not just Thailand). You may get one from your home country or you can get one in Thailand at the Department of Land Transport in Chiang Mai. However, you can only get one in Thailand if you have a 5-year Thai Driver's License.
(Source: Triptipedia)

Thai Driver's License

In order to qualify for a Thai driving license, you must be at least 18 years old, in good physical and mental health and hold a valid non-immigration visa. Although you must show that you are either living and working in the country or are living in Thailand on a retirement visa, some people reported that they can make a Thai driving license with a tourist visa. 

Your first license will be a temporary 1-year license which you can then renew for a 2 or 5-year Thai license depending on your visa. If you forget to renew you will have to start the whole process over again.
(Source: Expatden)

You can find all the requirements for either license here

If you have a valid driver's license and a valid motorcycle license from your home country, you should not have to do any driving test. If you do not have a valid motorcycle license from your home country you will be required to take a driving test. More information is provided (See: "Preparing for Motorcycle License Test") 

When you are filling out the application you have the option to apply for one or both licenses. It is highly recommended to do both so you don't have to retake the exams in the future if you change your mind. 

The following are needed and you will need 2 copies if you are applying for both car and bike license:

1) Medical Certificate (50-100 Baht)

Easily obtained from a local Doctor or Hospital. Must not be more than 30 days old.
This test will involve checking your height and weight, blood pressure and a color blindness exam.
The whole process takes just 10-15 minutes

2) Residency Certificate (500 Baht)

Proof of Address provided by the Immigration Bureau (Resident Certificate) or foreign embassy as provided.
Download Form
Go to Immigration section for more info on how to get this certificate

3) Copy of Passport and non-immigrant visa (original and photocopy)

(Face page; VISA page; current TM6 card; latest entry stamp page); bring your original Passport also.
Note: You cannot get a Thai Driving license on a Tourist Visa

4) Valid License or International Driving Permit

Your current country’s Motorbike or Car License or an International Driving Permit. Applicants without these will have to complete the road code and practical exams.
Holders of driver's licenses in a language not in English must have their embassy translate it and take that translation with them.

5) Application for Driving License

Application For Driving License
To see how to fill this page in go here

(Source: chiangmaibuddy)

You can renew your license up to 3 months before it expires. If it has been expired for over 1 year you will have to take the tests over again so make sure you renew! The Land Transport Office has a copier and a place to take photos if needed. The information desk will help with what floor

What you need:

1. Your temporary Thai driver’s license

2. A valid passport

3. A valid Non-Immigrant Visa

4. A residency certificate
   A work permit MIGHT be allowed instead, if anyone can verify this please update me!
   **See how to get a residency certificate at our immigration page)

5. Medical certificate (available as a walk-in service from Chiang Mai Ram hospital for 300BHT)

6. Approximately 2 hours total time (including transport)
   (Source: ChiangMaiBuddy)

Here’s what you have to do:

1. Arrive before 8:30am. Go directly to the Information Desk on the 2nd Floor (upstairs).  They will give you your renewal forms and tell you what copies you need. 

2. Go directly to the back and get copies as necessary.  You will need 1 for each license: passport front page, resident certificate, and health check.   If you are renewing 2 licenses, make a copy of each. 

3. Take you application, copies, passport, etc to counter 21 or 22**.   ( first two counters to the right as you come upstairs.  They will go through your documents and make sure everything is there. **This information about the counter may not be updated but information desk will help you

4. Proceed to counter 27 or 28.   They will take your documentation and tell you to move on to the lecture room (large room with TV) 

5. Proceed to the lecture room.  In a few minutes a proctor will come in and ask you to return to Counter 27 – 28 for some tests.

6. They will herd you all into the back or counter 27 and do a color/vision test.   I’ve never been asked to do a reaction test for a DL renewal.  Once finished, they will ask all to find your documents (all will be laid out on a nearby table)   For foreigners, you will be asked if you understand enough Thai to sit through the video.   This is not the time to be proud, say NO!  Trust me on this. 

7. Thais will be returned to the main lecture/TV hall and will have to sit through a refresher video of about 1 hour.  (Hopefully, you returned to your seat close to the door.)    Foreigners will be sat in another room and given an option to watch a video in English, Japanese, Chinese or Spanish.  (FYI for foreigners, they will keep your documents at counter 27.   Remember to come back for it here) 

8. In about an hour the proctor will return and shut off the TV.   You will be told to walk back out and get a queue number from the Information Desk (same desk as in #1).    This is why it is key to sit close to the door.    You can get queue #1 and be finished in about 15 mins.  If you sat in the back you may be queue #80+ and sit outside waiting for a few hours.   

9. When called, you will be told to come up and pay for the license(s) and any other fees necessary (address change, late renewal, etc)  Once paid, they will direct you behind the counter area for another queue number and to have your picture taken 

10. That’s it.    The picture is taken and the new card is printed almost immediately.   You’re done! 

(Source: CMStay)

If you have renewed your license recently please contact us to keep this information up to date!

The Land Transport Offices are located on Hang Dong Road, about 3 KM south of Airport Plaza on the left-hand side of the road just past Tesco Lotus and before the Big C. Hours are Monday to Friday  8:30 a.m. to 4:30 p.m.

If you have a license from your home country already:

1) Go to the 2nd floor of the Traffic department to window 21.  They will check your details and issue you with a number to wait to go at window 27.

2) At window 27 you will do 3 quick tests:

Color Blindness Test:
One of the officials will point to colored dots on a poster and you should respond by stating the dot’s color. You can answer in English but Thai is better:

Reflex Test:
Be seated behind an alternative gas and brake pedal and push the accelerator until the green LEDs start to light up. Hit the brake pedal before the LEDs reach the red zone. You will have to repeat this test twice.

Depth Perception Test:
Use forward and back buttons to align a moving pin with a fixed one, in a small box at approx. 10 meters distance.

3) Go to the main Information counter as you enter the second floor. You will have your documents checked again and be given another number.

4) When your number is called you will go to another window and pay the fees (usually window 21 but depends on the day): 205 baht for a car license and 155 baht for a motorbike. After this, you will be given another number and you sit and wait.

5) When your number is called, go to the back of the window area for your photograph to be taken. Here you will pick a number from a roll-a-dial and sit and wait. You will get your photograph taken and be issued with your license. 

The 1st license is a temporary license issued for 1 year (Green color). After 1 year a renewal is available for 5 years (Pink color). If you are a Tourist with a Thai Driving License you can only get a 1-year renewal.

If you are not used to the way Thailand works, taking a Thai-speaking person along with you will give you peace of mind (and some conversation) as you wait while the process is working. For those new arrivals or people without Thai friends, Chiang Mai Buddy offers the service of hiring your own local to assist you with the process.

If you don't have a license from your home country:

The above steps are similar except there will be a video you will have to watch along with reaction tests and a theory (multiple choice) test. This may end up being a 2-day process where you may finish the theory test the first day and then take the driving test the next day. 

PROCESS:

Submit application and documents between 8:00 - 9:00 am

Reaction tests and video 9:00 - 10:00 am (maybe longer)

Theory test (morning or afternoon they will let you know)

Driving/Riding Test
Make sure to wear pants. Skirts and shorts are not appropriate!

Receive a license and pay the fee

See the next section for more information about the theory and driving test

Preparing for the theory test

The test is 30-minute multiple-choice, which takes place twice each day (normally at 11 am and 3 pm). 

You can sit the exam twice at each sitting and requires a 75% pass rate. 

The results are usually given out within 20 minutes which is when you can arrange to book the practical test. 

You can see sample questions here:
Theory Test sample questions 1
Theory Test Sample Questions 2

And can try an interactive test here:
Interactive Test

(Source: motogirlthailand)

Taking the driving test

The practical test takes place in the DVLA center compound. Take your forms to the officer and wait to be called. Prior to taking the test you will be lined up with others and given an explanation of what to do. This explanation, however, will likely all be in Thai and the only explanation in English you will be given by the officer is to follow everyone else. 

The course involves using your turning signals, stopping completely at a stop sign and driving over a wooden plank (which is wide). 

As you get on your bike, make sure your helmet is buckled and just follow the line of people on the bikes also doing the course. Make sure you properly signal and stop when needed. 

When you have parked your bike and are walking to the officer DO NOT TAKE OFF OR UNBUCKLE YOUR HELMET. This is the last thing the officer will check and if you unbuckled or have it off they will fail you and you may have to do it again.

Once you have completed the test and given a pass stamp return back to the main building and hand in your forms. You will be given yet another number and asked to wait.