This is a cool subject. And great pics. In Calgary, there is a very vast system of these Bridges. They are called + 15. Because it gets very cold in our winter it can pretty much walk from pretty much any building to any building through the system. These are 15 feet off of the ground and the temperature in them is approximately 15 degrees which is why they get their name!
That’s cool that they have them there with the harsh winters you get it makes a lot of sense to have them there