Freedoms of movement are relative, as we learned by an Einsteinian thought experiment (posting of 31 October here). What does that help us with, in terms of planning transport?
I think it can help us understand why walking cities are better than automobile-cities, among other things.
When a certain amount of space enables higher freedoms of movements for more people, then it is more viable.
Let’s do another thought experiment! Imagine a walking street of 70 metres length with buildings on either side of a few floors. That entire space (only walking allowed!) can be packed with hundreds of people doing all sorts of things, from living, working, meeting, playing, reading, learning, etc.
Then imagine that street being re-designed to support fast through-transit by car. Oh! Where did the people go, and all their activities? Inside the buildings? Maybe a small proportion, yes, if they don’t mind the air and noise pollution, the confinement and restrictiveness of closed spaces, the physical risks outside the building, and so forth. The number of people and the number of functions, the overall freedoms of movement, shrink enormously, as the freedom of movement for a small group of car-users, expands.
The relation among bodies, described in posting of 31 October, gives us the chance to describe why transport forms that are
(a) high-vector and low-speed, e.g. walking and cycling
(b) low-vector and high-speed, e.g. fast train enable the use of overall space for more bodies

Aaron Thomas (http://aaronkmthomas.blogspot.com/)