The question, "Do speed limits matter?" hardly seems worthy of an answer. Insurance companies, police agencies, state transportation departments, and national safety organizations would have us believe that speed limits are a critical component of traffic regulation.

n the two years since Congress ditched the 55-mph albatross and gave states the right to establish their own maximum highway speed limits, fatality and accident rates have actually dropped.

In order to discuss the issue of highway fatalities, it is crucial to understand the differences between the terms "fatalities," "fatality rate," and the "fatal accident rate."

There comes a time when you know too much about a subject. A sure sign of this happening is when you're no longer able to answer a simple question on that subject without confusing the questioner. I've come to that point when it comes to talking about speed limits and their effect on highway safety.

In the mid-1970s, the U.S. Department of Transportation told us that the "55" mph speed limit saved 9,000 lives in one year. They didn't tell us that they changed the way they counted fatalities. They didn't tell us that most of the supposed life-saving took place on roads that had previously been posted at 55 mph or lower. They didn't tell us quite a bit.

The default posted speed limit, in the absence of very unusual circumstances that the driver cannot perceive, must be set at the 85th to 90th percentile level of free-flowing traffic under good conditions. The list of engineering references supporting this proven methodology is very long. Here are a few highlights:

This was a paper that was submitted by Charles Dornsife to the Transportation Research Board Annual Meeting on January 9, 2000.

The new information shows that fatalities have more than doubled on rural interstates and has also increased on rural primary highways. This information contradicts the state officials who claimed speed limits, higher fines, and more enforcement would lower traffic deaths

Isn't it interesting that the last year that insurance rates declined was 1973, the last year before the federal government decided it, and not the states should set highway speed limits? And, isn't it even more interesting that when the federal government gave up on its 55 mph folly and returned speed limit authority to the states, auto insurance losses began a continual decline