I’m currently re-reading Christopher Alexander’s classic ‘A Pattern Language’, whose deterministic design approach is the antithesis of Jane Jacobs’ in many ways, but less unfashionable than other rules-based systems due to its common sense approach.
I’ve noticed that Alexander’s notion of using pools of light to define spaces virtually is born out with alomost any feature.
In New York, where the sidewalks are rarely cleaned, one way to measure people flow quantitatively is through the dark spots on the pavement that chewing gum makes.
It seems that people will hang around pretty much any pole, lamp-post etc. One the other hand the pole must be high enough to provide ‘virtual’ shelter, there tends to be much less chewing gum around fire hydrants.