The Trucker 4 is a trucker that saw Homer as he jeopardizes their scam.
After Homer decided to drive Red Barclay's truck to Atlanta, he and Bart had to drive 2200 miles in 10 hours. Homer takes a bottle of pep pills to be up all night while driving. However, because he also took a bottle of sleeping pills to "balance it all out", he soon fell asleep at the wheel. The truck then proceeded to drive itself.
The next day, he was so amazed that after he had stopped the truck, he told two truckers about it. They explained to him that every truck has the Navitron Autodrive systems installed inside so they can drive themselves. The two truckers then threatened Homer to keep quiet.
Despite of Homer's promise, he soon told some tourists about the scam. The two truckers and three other truckers then chased Homer in their trucks, forming a blockade, but Homer got past them without using the Autodrive system, after the Autodrive system bailed from the truck.
Eventually, one of the truckers suggested to stop using the Autodrive system and go back to using their hands and wits. However, they all refused it and decided to smuggle Beanie Babies as their new scam instead.