Almost every speed limit is too low

Almost every speed limit is too low
"When lieutenant Gary Megge of the Michigan State Police attends a meeting, he sometimes asks, “How many of you broke the speed limit on your way here?”
Hearing his question, you might assume that lieutenant Megge is a particularly zealous police officer. The type of person who walks half a city block to avoid jaywalking on an empty street.
The model citizen who defers almost obnoxiously to the letter of the law.
But that is not the point of lieutenant Megge’s question at all.
“We all speed, yet months and months usually pass between us seeing a crash,” lieutenant Megge tells us when we call to discuss speed limits.
“That tells me that most of us are adequate, safe, reasonable drivers. 
Speeding and traffic safety have a small correlation.”
Over the past 12 years, lieutenant Megge has increased the speed limit on nearly 400 of Michigan’s roadways.
Each time, he or one of his officers hears from community groups who complain that people already drive too fast.
But as Megge and his colleagues explain, their intent is not to reduce congestion, bow to the reality that everyone drives too fast, or even strike a balance between safety concerns and drivers’ desire to arrive at their destinations faster.
Quite the opposite, lieutenant Megge advocates for raising speed limits because he believes it makes roads safer.
TRAFFIC ENGINEERING 101
Every year, traffic engineers review the speed limit on thousands of stretches of road and highway. Most are reviewed by a member of the state’s Department of Transportation, often along with a member of the state police, as is the case in Michigan.
In each case, the “survey team” has a clear approach: they want to set the speed limit so that 15% of drivers exceed it and 85% of drivers drive at or below the speed limit.
This “nationally recognized method” of setting the speed limit as the 85th percentile speed is essentially traffic engineering 101.
It’s also a bit perplexing to those unfamiliar with the concept.
Shouldn’t everyone drive at or below the speed limit?
And if a driver’s speed is dictated by the speed limit, how can you decide whether or not to change that limit based on the speed of traffic?
The answer lies in realizing that the speed limit really is just a number on a sign, and it has very little influence on how fast people drive..."