Know your limits when it comes to speed

By: Eric Czarnik | C&G Newspapers | Published June 29, 2015

The urge to hurry can put a driver at risk of a speeding ticket or even a traffic accident. But even if a speed limit seems like an inconvenience, there is often a carefully considered reason behind the numbers, according to road and safety experts.

According to a document from the Michigan Office of Highway Safety Planning called “Establishing Realistic Speed Limits,” speed limits are designed to keep all drivers as safe as possible while staying within realistic boundaries of “reasonable and proper” public driving habits.

The document says speed limits are set by the authority that governs the road in question — be it a municipality, a county road agency or the Michigan Department of Transportation. When designed, speed limits are supposed to take the road surface and motorist patterns into account. The limits may be changed at the request of residents or evidence of need, such as broad noncompliance or accident increases.

The publication says, “Contrary to popular belief, lower speed limits do not necessarily improve safety.” It says the goal instead is to keep as many drivers as possible flowing at a synchronized speed, averting the chances of risky behaviors such as tailgating and weaving.

“The primary basis for establishing a proper, realistic speed limit is the nationally recognized method of using the 85th percentile speed. This is the speed at or below which 85% of the traffic moves,” the document says.

Sgt. Tim Fitzgerald from the Michigan State Police said the engineering of the roadway as well as access points such as driveways and crosswalks are also considered when determining an appropriate speed limit.

“It’s sort of a total package,” Fitzgerald said.

Susan Hiltz, AAA Michigan public affairs director, recommended strictly following all speed limit road signs and keeping a vigilant eye on the speedometer.

“I think the posted limit is what most of us need to keep in mind because that is what law enforcement will be looking at,” she said. “Following the rules of the road means following the posted speed limits.”

But she said drivers need to adapt and react to stormy or perilous weather on the roads by slowing down.

“Obviously, when you have challenging road conditions like rain, sleet or snow, definitely everyone needs to be more cautious,” she said. “You need to take a more cautious approach to driving in poor conditions like that.”

Hiltz also said lower speed limits do generally tend to make driving less dangerous.

“It really stands to reason that if you are going at a slow speed, you have a better chance of stopping if there is a potential crash,” she said. “Plus, the chances are that the impact will be smaller.”

Learn more about AAA Michigan by visiting Learn more about the Michigan Office of Highway Safety Planning by visiting Visit the Michigan State Police’s website at