This speed limit sign, posted by Michigan Department of Transportation in 1955, changes depending on how the light hits it.

In 1955, Al Kaline led the Detroit Tigers and Major League Baseball with a .340 batting average and, stop me if you've heard this one before, the Lions went from first place in the NFL in 1954 to last. Ford made its first public stock offering while Ray Croc opened his first McDonald's restaurant in Des Plaines, Illinois. Kids across the country were getting to know Annette, Tommy, Darlene, Cubby and the other Mousketeers on a brand new ABC television show.

Using a new process that was pretty high-tech for Eisenhower-years, MDOT put up highway speed limit signs that changed if you looked at them during the day or at night. Michigan's daytime speed limit was 65, but slowed by 10 mph after dark. The reflective signs hid part of the "5" behind the "6," giving the single sign dual usage. The changes in Michigan speed limits were day and night- literally.

Do you think the "Laurel or Yanni" defense might work if you got a speeding ticket?

Bonus Video: Michigan's Quietest Highway - Michigazetteer