Sam Lor, which means three wheels, are tricycles with a passenger compartment big enough for two people. However you will sometimes see three or more people riding in them. Most of the drivers are older men, who must have legs of steel. You will find Sam Lors mainly in downtown area of Ubon Ratchathani.
Sam Lors are slow, quiet and reasonably priced. You need to negotiate and agree upon a fare before you get onboard. You should try it at least once. I don't know how much longet they will be around. There aren't many young Thai men who have a dream to be a Sam Lor owner/operator