Unlike the curries and stir-fires that you commonly see in Thai restaurants around the world, which are meant to be shared, much of the food you will find on the street consists of individual dishes that are made for just one person. “Single dishes” (jahn deeo) almost constitute a separate cuisine from the Thai foods that you are probably familiar with. Although most curries and stir-fried dishes can be, and frequently are, made in single serving sizes, there are a wealth of other foods that are really only ever seen as individual dishes.
Egg Noodles with Red Pork - A typical 'single dish'
Stalls and carts selling single dish meals are at their busiest around lunch time, and many places may operate only during the mid-day hours, although others in residential areas may only open in the evening, and there are even some that specialize in the late night hours, serving up easy to digest foods for those that still aren't ready for bed after the bars and nightclubs close.
Food carts for single dishes tend to be quite modern affairs, all stainless steel and clear plastic. Thais are rather fastidious about food, and insist on cleanliness when selecting where to eat. Carts that appear dirty or unkempt will soon lose custom. A typical cart will be a little less than a metre wide, and around two metres long. They will be set on two large wheels the size of bicycle tires in the middle of either side, with a third small wheel under one end. The other end will have a handle for pushing the cart when it needs to be moved. Noodle carts will have a gas burner for heating the large pot of stock for cooking the noodles.
Some carts are built as side-cars on motorcycles so they can easily be moved from one spot to another. Recently, I've seen 'carts' built into the bed of small pick-up trucks, which no doubt makes them easier to move around, plus provides extra space to store folding tables and stools.
Single dishes make generous use of those two basic staples of the Thai diet: Noodles and rice. While rice is heavily identified with Thai cuisine, noodles form no less important a part of the foods that Thais eat. In fact, I think it can be argued that most Thais can live without rice, but not without noodles. Noodles are the base for most single serving dishes, although it's a slim majority at best.