It's an interesting read. The story is that safety becomes paramount in automobiles. With the eventual evolution of people driving these safe vehicles and making a game of wrecking anyone not driving one of these vehicles.
http://www.2112.net/xanadu/articles/a_nice_morning_drive.htm
I believe the term is “risk compensation.” If people feel more at risk, they behave more carefully; conversely, if they feel less at risk, they behave less carefully.