The naked woman, and the hitchhiker in black

I think its more than what it seems on the surface. I believe the pretty girl on the bike represented life and youth, and when Kowalski turned her down, he was turning away the chance to live, instead choosing death, which the hitchhiker in black represented. When he gave in to her, his fate was sealed. As he was nearing the blockade, he smiled because he knew she would be waiting for him on the other side. When she told him she'd been waiting for him for a long time, he knew they were soul mates, destined to go hand in hand into the ever after. In smashing into the bulldozers, the bonds of his tragic life were loosened. The peace Kowalski had been searching for had been found at last.