The intersection of Michigan Ave and Woodward is marked by the policeman I added. In the first pic, from 2002, the streets still intersect with four corners.

A couple years later, however, the City redesigned the intersection which now circles around Campus Martius park.

And now the area where Michigan Ave and Woodward connect is Campus Martius. In the winter months, the City turns a portion of the park into a skating rink. Very New Yorkesque.

Of course, as it turns out, facebook lied. Today is not the anniversary of the first tri-color signal. Apparently it was in October of 1920, not December 1920.
:)
Oh well. It's still cool to look back at pictures of the area before Campus Martius, even if we didn't learn anything new today.