I also found quite a few of these in Tokyo. Many-block-long ped tunnels that connected nearby subway stations together, but also served as a way to cross town without being out in the blazing heat and humidity.

The skyway in Minneapolis was maybe my first experience with this type of infrastructure, and it was a merciful respite from the winter cold at the time.

In the modern world, I have to believe these pedestrian thoroughfares will increasingly serve in avoiding the summer heat.