What Do Those Numbers on the Mackinac Bridge Really Mean?

If you haven't noticed them before-- now you will!

It's been probably 15 years since I last crossed the Mackinac Bridge. Too long, I know. The next time your travels take you to Michigan's scenic Upper Peninsula keep an eye out for these peculiar signs located along the Mackinac Bridge.

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With the kids' last day of school upon us and Memorial Day behind us, the summer season has unofficially begun in Michigan! No doubt thousands of travelers will make their way across the Mackinac Bridge to cross items off their summer bucket list. Popular destinations in the U.P. include Tahquamenon Falls, the Soo Locks, Kitch-iti-kipi and Pictured Rocks.

According to the Mackinac Bridge Authority, the independent state organization which oversees daily operations on the bridge, and the Mackinac Island Tourism Board,

More than 4 million vehicles cross the Mackinac Bridge each year. In July and August, the busiest months of the year for the “Mighty Mac,” bridge traffic averages 20,000 vehicles per day.

Once You See It, You Can't Unseen It

However, I'd be curious to know just how many of the 20,000-some travelers the Mackinac Bridge sees each day have noticed these strange numbers along the bridge:

I hadn't noticed until the unofficial Facebook fan page for the Mackinac Bridge, MightyMac.org, clued me in writing,

If you wonder what these numbers are on the Mighty Mac, they are the numbers of the piers supporting the bridge. They are numbered from the south to the north and the towers are piers 19 & 20

Well, that actually makes a lot of sense, doesn't it?