What metaphors are used in Crash by J. G. Ballard?

Much of the narrative is a metaphor for modern technology in human relationships. The main character of this novel survived a terrible car crash and meets a man who also survived a crash. Both men are obsessed with car accidents and how they change a person's life. The main character, James Ballard, goes along with his new friend's obsession, cruising the highways looking for car crashes. Unfortunately, there is never a lack of crashes to find. Ballard becomes aware that there are highways everywhere and it seems that every time there is a crash it is like a dress rehearsal for the ultimate death, for the moment when all humans will perish from the use of the technology they have come to rely on.