Mystery solved! I always wondered what the deal was with that strange interchange on I-94 (Ford Freeway) at Woodward in Detroit. Eastbound, for instance, you go under Woodward, then shoot off on a bit of a siding, which continues east, but to exit, you go onto John R Street and circle back to Woodward. What were they thinking when they built that?

Well, this article and picture answer the question. There were originally stairs leading down from Woodward to the freeway, where pedestrians could link to a planned rapid bus system that was supposed to run on the expressways. Check it out here.

So the idea was that the rapid busses would pull off of the freeway onto the siding, pick up passengers, then re-enter the highway. That would make too much sense. It never happened. Somewhere along the way the stairs disappeared, and we were just left with a crazy interchange. That sounds like the downtown People Mover, which was designed to be the end section of a rapid rail system that ran out the spoke avenues from downtown. The rail system was never built, so the PM is left to circle endlessly, shuttling people around downtown in its counter-clockwise circuit. I'm beginning to see a pattern here.