Taxis from the public taxi stand at the airport cost a flat USD15 (October 2019), and tuk-tuks cost USD7 officially. Cash Only. If you are willing to lug your bags outside the airport fence you can catch a tuk tuk into town for USD5-6 depending how hard you bargain. If you want to avoid bargain you can order tuk-tuk using PassApp application(you will need a local sim card). The waiting time is not more than 3 minutes and price will be around USD4 to the city center (Nov 2018). When you finish your ride application will show the total price. For visitors on a budget without a lot of luggage, you can catch a motorcycle officially or unofficially, though be aware this ride can be extremely uncomfortable especially if you arrive during the afternoon or morning rush hour the trip can take about an hour in stop and go traffic. If you do catch a motorbike, the older types with the large flat seats are much more comfortable than the newer ones. A motorbike ride during rush hour on the back of a small seated newer bike is likely to be a very strenuous experience and highly not recommended. An expressway is in the works but in the meantime, it may take an hour to an hour and a half to get from the airport to the city depending on the severity of rush hour traffic.
Be aware during rush hour (3-8 pm) riding in on a tuk tuk can be very dusty and polluted with traffic fumes. If you are sensitive to this, taking a bus or taxi is recommended.
While tuk tuk is THE way to get around, note that some drivers cannot read a map, so that pointing out a destination on a map may result in a prolonged conversation with random locals!