Unsafe at any time, or speed?

I always wear my seatbelt. That said, there seems to be an odd lack of correlation between accident fatalities and the rising use of safety equipment in cars. Columnist Andrew Ferguson writes:

Traffic fatalities, per mile, are a fraction of what they were 50 years ago, for multiple reasons: better roads, safer cars, fewer drunk drivers -- and greater use of seat belts. Yet the cause-and-effect evidence is complicated.

Last year, for example, according to the American Automobile Association, U.S. seat belt use had its highest single-year increase in eight years. At the same time, traffic fatalities rose to their highest level since 1990, according to the National Highway Traffic Safety Administration.

Jeremy Lott has a go at this subject too. You might find what he has to write interesting as well.