The number of people killed in traffic accidents in the Netherlands has dropped 80% since the 1972 high of 3000+/year. It is now at 640/year.

The main reason being given is seat belts for drivers and helmets for moped users. Info in Dutch from the official statistics bureau: http://www.cbs.nl/nl-NL/menu/themas/gezondheid-welzijn/publi...