Slower Does Not Mean Safer

Do you believe, as I do, that speeding laws are just another way for governments to generate revenue? No, says government, we're trying to keep you safer. Bullshit.

I saw a good article recently that discusses some facts. From the National Motorists Association:
"Speed Limits: Slower Does Not Mean Safer"
http://blog.motorists.org/speed-limits-slower-safer/

Before you dismiss this as just more propaganda from a group that opposes arbitrarily low speed limits, notice this study was done by the Michigan State Police:
http://www.michigan.gov/msp/0,1607,7-123-1593_47093_25802-87384--,00.html

Here are direct download links from the Michigan State Police website:
Establishing Realistic Speed Limits Booklet
Establishing Realistic Speed Limits Pamphlet


Back to the NMA article...
"As we’ve noted many times in the past, speed limits are the most safe when they are set using the 85th percentile speed. Numerous studies have shown that the 85th percentile is the safest possible level at which to set a speed limit..."

Why is this true? From the MSP booklet:
"Historically, before and after traffic engineering studies have shown that changing the posted speed limit does not significantly affect the 85th percentile speed. The driving environment, which includes other traffic on the road and roadway conditions, is the primary factor which influences the prevailing speed. The driving environment is reflected by the 85th percentile speed. The majority of drivers, consciously or unconsciously, consider the factors in the driving environment and travel at a speed that is safe and comfortable regardless of the posted speed limit."

"Unfortunately, most speed limits are set well below the 85th percentile speed. When speed limits are set too low, drivers are forced to travel at a speed that increases their risk of being involved in an accident. The alternative is to travel at the safest (85th percentile) speed and risk a speeding ticket. This is something that many drivers do everyday."

Wow, how about that? Some recognition of reality by the MSP! Unfortunately, this thinking doesn't translate into action. If you've ever driven on M28 between Wakefield and Bergland you know what I'm talking about.

Anyway, back to the MSP booklet:
"Contrary to popular belief, lower speed limits do not necessarily improve safety. The more uniform the speeds of vehicles in a traffic stream, the less chance there is for conflict and crashes. Posting speed limits lower or higher than what the majority of drivers are traveling produces two distinct groups of drivers: those attempting to observe the speed limit and those driving at a speed they feel is reasonable and prudent. These differences in speeds can result in increased crashes due to tailgating, improper passing, reckless driving, and weaving from lane to lane."

I completely agree with the NMA's conclusion:
"The key to improving traffic safety isn’t slowing everyone down, it’s getting drivers to travel near the same speed. This is something that the 85th percentile accomplishes naturally. It may seem counter-intuitive, but it’s the truth."