The Loop is two cities stacked. There is the one above, where the sun rakes east along Madison from 11 to 2 and the wind off the lake does very little for you in July. And there is the one below — the Pedway — forty-odd blocks of glass tunnels and basement concourses connecting the train stations, the banks, and the older department-store buildings. It is climate-controlled, signed badly, and unknown to most people who work above it.
The walks below treat the Pedway as a normal piece of the routing graph. Each pick surfaces and dives a couple of times, using street-level arcades — the Rookery, the Inland Steel ground floor, the marble run between Block 37 and Macy’s — to bridge gaps where the tunnels don’t go. Shade scores assume the surface portion at midday in July.
A note on the Pedway map: the city version is incomplete. We use the Friends of the Pedway tracing, which catches the privately-maintained connectors through the Hyatt and the Aon. If your route ducks underground and the door is locked on a Sunday, that’s on us — re-route, and tell us.