Although this might seem quite weird to you, the reasons, why such a question springs up are as follows: shoes are expensive; hot climate; personal habits. Although there are practically no DOT or any other regulation in any of the 50 states that would prohibit driving barefoot, practically speaking, this is almost impossible for a truck driver. Operating pedals to respond quickly to a situation on the road requires stability provided by proper shoes. Let alone a situation, when a driver has to quickly spring out of the truck to fix a problem or to put a triangle in the case of a sudden road accident.