Despite being co-written by Alias creator J.J. Abrams, this is disappointingly lame in the script department. The potential of an unstoppable nemesis menacing an innocent driver has been used before, not least in Duel and The Hitcher, but the former was a Spielberg movie, and the latter had Rutger Hauer - both of these will help paper over a lot of cracks. By sheer charisma, Hauer's preternatural resilience became plausible, but here, there is no explanation given for how the vengeful trucker, upset by Walker and Zahn's CB pranking, follows them - a 16-wheeler isn't the sort of thing you can hide behind a plant-pot.
The film also has at least one character too many; Zahn's dumbass is endearing stoopid, most memorably when disarming a potentially explosive situation in a redneck bar, but does little in the second half. Sobieski, the platonic "friend", appears to exist merely in order to be rescued, since one guy rescuing another might be perceived as dubiously homoerotic (especially if David DeCoteau was directing...). These two should perhaps have been combined - or, better still, one of them murdered early on, in order to establish a level of threat that is surprisingly lacking. The DVD contains no less than four - count 'em, four - endings, but we haven't bothered. If the one finally chosen was actually the best, dread to think what the others are like.