Nobody seems to know.
Maybe it's a video game. Soon the expressway metamorphoses again, becoming plain old Millbrook Road, but it's too much of a subtlety for some drivers, who continue their blind zooming. We hit Skinker and are now in the city limits, where the Forest Park Expressway gets neat again. This is probably what Route 66 was like, a slender two-lane highway winding its way to an urban conclusion. It's a shortcut that goes a long way to get you there faster.