Dennis Weaver's character finally got sick of running - he turned his car towards the rogue truck, jammed it's throttle, and watched as the truck drive, blinded by smoke from the wreck of Weaver's car, pushed it over a cliff, and was unable to avoid his truck following the same route to the cliff bottom. The reaction of Weaver's character was an almost primal 'victory' dance as he saw his tormentor destroyed, but then his natrual character regained control, and the film ended as he sat on the cliff edge watching the sunset, and pondering ... who knows what.