Why Are There So Many Mile Markers on I-94?

May 10, 2018

Fifth-of-a-mile markers on Interstate 94 near Kalamazoo.
Credit Sehvilla Mann / WMUK

Bonnie Nye does not love driving on Interstate 94. In fact, now that she's not commuting, the retired nurse from Lawton says she avoids that road "like the plague." But she does have a question about it. 


Nye has noticed that at least one Southwest Michigan stretch of I-94, the one between Mattawan and Kalamazoo, has extra location markers. Instead of one sign every mile, there's a sign every fifth of a mile. Mile 70, for example, has a marker at 70.2, 70.4, 70.6 and 70.8 miles.  Nye wonders why this road has so many markers.

“Somebody had suggested, and I hadn’t thought of this before that perhaps it’s for if there’s an accident, the responders, first responders, if you can tell them you’re at 67.2 instead of somewhere between 66 and 67, or 67 and 68 or whatever, it would be easier for them to locate the accident. Maybe that’s the reason, I’m not sure,” she said.

Or, she added, maybe trucks use the signs for navigation.

After driving by some of the markers, Nye and I exit I-94 and park at the Michigan Department of Transportation-Southwest Region office in Kalamazoo, where we meet MDOT spokesperson Nick Schirripa.

Schirripa says that in his recollection, some areas have had extra mile markers on their roads for decades.

“The first time I saw them was probably 20 years ago in Chicago, the greater Chicago area. Obviously with the spaghetti bowl they have there of highways and interstates, it’s a lot more necessary there,” he said.

And it’s not just Illinois. Schirripa says in the Great Lakes region alone, Indiana, Ohio and Wisconsin also put extra markers on some roads.

Schirripa says Michigan uses fraction-of-a-mile markers along some roads with heavy traffic, which helps to explain why you’ll see them on I-94.

He adds that if traffic increases on the Southwest Michigan parts of roads like I-69 or U.S. 131, you might see the markers there.

“That’s a tool we have in our toolbox, but I couldn’t give you a date. I don’t think anyone can really anticipate when that will happen.”

Each sign sets MDOT back about $100, according to Schirripa, a cost he describes as modest over the long term.

But why put a marker every fifth of a mile?

That’s what Bonnie Nye wants to know, and Schirripa says her first guess was right. The markers help first responders to pinpoint an accident.

“Seconds are important,” Schirripa said. “And it’s not just in responding to whatever that incident is. Obviously if we have an incident on I-94, whether it’s a crash or just a disabled vehicle of any kind, that poses a safety hazard for everybody else traveling that direction. So we need to get that cleared as quickly as possible.”

Plus, if you’re broken down on I-94, you might like to know where you are. Schirripa says that’s easier with more markers.

“You’ll be able to see one of those mile markers from wherever you are. If it’s a little bit too far ahead of you to see, look on other bound and it’ll be right behind you, you’ll be able to see where it is,” he said.

Some states go even further to make sure drivers can see the signs, with a marker every tenth of a mile.

If you see lots of markers while driving on the Interstate, I ask Schirripa, should you be nervous? Does it say something about the safety of the road?

“It doesn’t necessarily mean you’re more prone to a crash,” he replied. “It just simply means that there are probably more vehicles traveling the same way you are. And I think if you notice them, if anybody notices them while they’re driving, suddenly you’re more aware of where you are.

“And being more aware of your surroundings makes you a safer driver, just inherently,” he said.

Nye, who noticed the markers and wondered what they were for, says it makes sense that they are there for emergencies.

“As a retired nurse I can see where that’s really helpful,” she said.

Whenever something in Southwest Michigan makes you ask, "Why is that?” let us know.

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