Chapter Two of Grapes of Wrath opens with description of a "huge red transport truck" standing in front of a restaurant. The passage is as follows.
A huge red transport truck stood in front of the little roadside restaurant. The vertical exhaust pipe muttered softly, and an almost invisible haze of steel-blue smoke hovered over its end. It was a new truck, shinning red, and in twelve-inch letters on its sides-OKLAHOMA CITY TRANSPORT COMPANY
The truck could be just the color of the company it represents. If it signifies anything, however, it would be communism, or the workers fight for their rights and the end of oppressive working conditions under the reign of rich business owners.
In this chapter, the story's main character Tom Goad asks the truck driver if he could be a good guy and give him a lift. The driver points out that he has a "No Riders" sign in his window shield, but Tom changes his mind by telling that he was obviously forced to carry the sticker "by some rich bastard."
The driver's affinity with Tom as a fellow worker becomes more apparent as their conversation continues. At one point he states an ability to notice if people are workers are not. "Thought so. I seen your hands. I notice all stuff like that. Take a pride in it."