The Curious Case of Michigan’s ‘Fat Diamond’ Road Signs

Drivers in Michigan pass by various road signs mile after mile on the trips they take. The shields that indicate the routes a driver is on or intersecting are among the most vital. Signed highways are generally in three main categories: Interstate, US Routes and State Roads. (A smaller category of county road signs exist but is not uniformly used.)

Michigan's state routes are the well known 'M' highways and always appear within a diamond shape. From M-1/Woodward Avenue in the Detroit area to M-553 near Marquette, there are hundreds of these highways across the peninsulas.

An odd thing happens with the 3-digit routes, they often, but not always, get a 'fat diamond' road sign.

Take the example from M-121 at its eastern endpoint at I-196 at the Grandville/Jenison border. This sign has a 'fat diamond' the diamond is wider than it is tall to accommodate the 3 digits of the route number.

READ MORE: What is the Difference Between I-96 and I-196 Freeways

Take this example from M-179 between Kalamazoo and Grand Rapids near Gun Lake. The left side of the image is M-179 in a 'fat diamond' and on the right is the same highway number squeezed into a diamond designed to accommodate just 1 or 2 digit highway numbers.

It's not just three digit state highways that get the squished sign practice. Of of three digit US highways that run through Michigan (there are three, US-131, US-141 and US-223) all could get the squeeze at any time like this sign for US-141 in Crystal Falls.

And 3-digit Interstate highways as well. I-194 in Battle Creek sports skinny and the more proper wide shields.

What makes the use so odd is there appears to be no rhyme or reason as to when the 'fat diamond' shields get deployed and when they don't. For what it's worth, Michigan's elongated diamonds are not the worse example of stretching out highways shields to fit larger numbers. States that use their outline as the state highway shield like Ohio, Alabama and Georgia look a little ridiculous with their chubby state outlines like these two in the Toledo area, a sign assembly 4400 feet from the Michigan state line.