How does Uncle Hammer get away with crossing the bridge first even though the truck was already on it? Why do you think he does this?

Initially, Uncle Hammer gets across because rather than back up..... he speeds up. He also pulls it off because very few black people own cars, let alone a Packard. The passengers of the Model T think the car belongs to Mr. Wallace because he's the only one who can afford one. Thus, they allow Uncle Hammer to pass because Granger is white, and they're expected to let him pass first.