These are cyclos. They are bicycles with “carriages” attached to the front.
These cyclo drivers (I understand) come to the city (in this case Phnom Penh) from the country to make some money. Note the device in the back of each bike; I believe it is a brake. We each hired a cyclo driver to take us from one spot to another, probably a 15 or 20 minute ride. The cost was $1 each. The drivers were happy to pose for us.
These guys sleep in their cyclo or in a hammock attached to the cyclo, as they have no other home, at least in the city.