While in Chiang Mai, I found the easiest way to get around was by Songtow (or Songthaew). I was trying to write something about it when I found a very good article on the internet describing this mode of transportation.
From McCartor.com :
Songthaews [pronounced song-tao] are pickup trucks that function as taxis in Thailand.
The trucks have a large metal framed unit fitted onto the back. Ever had a neighbor with one of those things in the flatbed of his truck that makes it into a camper? Theyre kinda like that.
The mostly-enclosed back area protects passengers from rain or, more often, from the hot Thai sun. Long pieces of tinted plastic serve as thin windows on each side. Running the length of the inside are two long cushioned benches. This is where the name comes from; songthaew is Thai for two bench(s).
Passengers enter through a doorway-like opening in the very back. Where the tail-gate would normally be there is a step or two to help you get in. To the left and right of the opening on the outside there are places for people to stand and hold on if the trucks really full. More rurally-based songthaews may also have a small luggage rack on top useful for transporting big bags of goods to and from market.
Just so you know, there are different colored trucks. These different colors give you an idea as to where the particular songthaew goes. If youre a visitor to, say, Chiang Mai, most likely you’re going to be using the red songthaews. Reds circle around the moat, serving both the old city (that is, inside the moat) as well as popular outlaying spots (Central Airport Plaza, Kad San Kaew, maybe Tesco-Lotus). Depending on the time of day, the red ones may also swing by the airport, the bus depot, or the train station.
Yellow songthaews in Chiang Mai are the ones that head to smaller towns twenty, thirty kilometers away. These are more like your commuter trains; long straight trips with just a few stops. I dont think they take people exactly where they want to go. Rather, they take everyone to a central place in a town and then head on to the next one.
Ive heard tell of blue songthaews in Chiang Mai, but like Nessie, never actually seen them. It makes sense that theyd have the third primary color, but I don’t want to go telling tales outta school.
Now, when you want a taxi you usually have two choices: you can call the taxi company or you can try hailing one. Songthaews are old school offering only the latter option.
Okay, youre standing on the sidewalk. You see a songthaew coming a block or two away. Is it the color you want? If so, extend one arm out towards the street (usually this would be your left arm). Now dont go raising you arm all like Taxi!; but rather, put it down at a 45 degree angleas if you were pointing to a crab on the ground seven feet away from you. With your palm facing down, swing your four fingers towards your palm a couple of times (kinda like how kids wave when theyre really little or Bart Simpson demonstrating the sound of one hand clapping).
The truck will pull over if he can; if traffics too heavy he might not be able to stop right there. Go to wherever he stops, but dont get in yet. Walk up to the passenger window of the cab (in Thailand cars drive on the left-hand side of the street, the right-hand side of the carlike England) which will be open at least a little bit. Tell the driver where you want to go, poised more as a question. Airport?..
If he (Ive yet to see a female songthaew driver, although I have seen one female tuk tuk driver) shakes his head, thats too far out of his way or not an area he covers. If, however, you get a nod then hell take you there. Songthaews dont have any sort of meter like a taxi, so (especially if youre a farang) youll want to agree on a price before getting in. Fifteen baht? Ok. Once that’s sorted, get moving and get yourself into the back.
Overall, I found thm a good mode of transportation. They get you where you want to go and they are cheap.