$1\mathrm{.}2.$ Many cities in the world have CBDs that are surrounded by ring$-$radial street networks. Assume one such city has a circular CBD with radius, r$>0,$ and that a fraction p of the CBD area is occupied by skyscrapers with n floors. The average space per employee a$,$ the street spacing s$,$ the street capacity q$,$ and the vehicle occupancy k are assumed to take the values of the example of Section $1\mathrm{.}1.$ Given this information, estimate values of the commuter demand $[$commuters$]$ and the perimeter roadway capacity $[$commuters$/$hr$].$ then show how the duration of the rush depends on r$,$ n$,$ and p$.$