This has a real movie feel about it.
It’s a relatively short book that does the movie thing of introducing its larger than life action hero, then giving him a quest/adventure building to an obvious climax. In this case our tough as teak bikie is taken out of maximum security, because of his preternatural driving skills, to deliver vital medicine across to the other side of post-apocalyptic US - LA to Boston. Along the way he has to battle mutant animals, fatigue, betrayal, mega-storms, and, in a classic filmic climax, bikie gangs.
The mood is able, as is the setting, although the latter isn’t really detailed (post apocalyptic has been travelled so frequently these days: we're in the land of Mad Max). Maybe it received some more critical acclaim at the time because it was still original to have an ‘antihero’ – ‘Hell’ Tanner is a brutally unsubtle device in opposition to clean cut good guys. But these days (and then?) he is deep in the land of stereotype that Bruce Willis or Nicholas Cage or Van Damme or any of a number of ‘wrong-side-of-the-tracks’ sullen heroes could be cut from. Zelazny goes way too far with this, contradicting himself totally in his absurd romanticism of the lone bikie justified by his own code and his raw toughness. He casually throws in that he’s a rapist and a murderer of innocents to set up the anti-hero, but throughout the book ‘Hell’ only ever does honourable things, getting downright homey and sentimental with a salt of the earth farm family and their kid, and stepping in as the knight to rescue a bikie damsel in distress. He only ever fights in self-defence or to protect others: the anti-hero thing is pure gloss.