What is the theme in Crash by J. G. Ballard?

Obsession is a theme in the story. After experiencing a car accident, James Ballard finds that he is obsessed with cars and accidents. Ballard looks at the injuries on his body and feels as though his car has left its mark on him, somehow becoming a part of him. Ballard goes home and notices for the first time how many roads there are right outside his home and how many accidents there are on any given day. Ballard begins to think that all of humanity is moving toward a massive accident that will end life on the entire planet.