Uploaded on 2017-04-23 by Giuseppe Venditti

I like very much the notion of "relationship between the different flows", and how the flows are mutually linked. Let's examinate e tipical european old city, not well planned: Rome; and let's take our focus on the probably most important stock and flow: people. We say to have about 3 million resident people, and 1 to 1.5 million people that every day come in and go away from the city; the numers are not exactly, but they are very close to the truth. More, the every day flow is not the same during the year, because we must consider the tourist flow, that is lower in winter and higher in spring and summer. So we note three factors: - first of all a resident group of 3 million peolple, the hard core of the city; - second, 3/4 million people who come every day to work (commuting people); - third, from 1/4 to 3/4 million people who come to visit the city. In other words, the city has in charge every day from 1/3 to 1/2 more than the resident citizens; this number is a hard test for transport, food and general services (every day shopping, fashion shopping, for example). I would take into account only the three following important aspects of the lifes of the three categories of people living in Rome every day. Because of the dimensioning of a general service has to be set on the peak, the problem to solve is to optimise the three different services (transport, food and general services - and what from they originate). The natural result of the problem is a better planning (or it should be), and could suggest different politics about commuting and tourism, The interesting fact is that without studying the flows we can't afford any problem of the city, because in my opinion the flows are not a simple phenomenon of the city, but rather the intertwining of the flows is THE life of the city.