How many fully-grown people can you stuff into the back of a compact songthaew, literally ‘two benches’? People are always willing to try and find out. They go to the store. They go home. To work. Kids take them alone sitting among strangers. And all for usually around 10 baht.
These modified pickup trucks operate as public communal taxis. Once you get in and find a tightly packed space to sit, these are simple enough to figure how to operate. Generally they go on a fixed route, or one slightly modifiable based on its passengers needs. Then, when you are ready to get out you press a small buzzer button to indicate to the driver in the cabin.
The most difficult part, aside from finding adequate headspace, is figuring out which one is going your way.