couldn't take enough pressure of the accelerator to slow down the fraction of a mph faster he was going to match the speed of the truck he was following.
And as said though he thought he could, he didn't have the power to get past fast enough to the liking of those four wheelers who are being allowed to use the truckers roadways.

There used to be a truck and trucker in Montana that drove a vintage Peterbilt, '60s era I believe. Now this truck wasn't what it appeared to be...a classic old semi meticulously restore. No, under the cab and hood was a modern powerhouse and drive train as well as state of the art suspension. The drivers motto was, I can pass anything, anytime and anywhere. He'd routinely pass a string of other trucks and cars while climbing up any one of the mountain passes leading through the Rockies. He even passed me while I was on my motorcycle climbing up Rogers Pass (Hwy 200) near Lincoln, MT. I was doing 70mph up the hill and he went by me doing over 100mph with fully loaded 53' trailer! I think it might have had something to do with the twin turbo superchargers. He didn't measure mpg...but gpm!