Nick Paumarten's article "The lives of elevators" in last week's New Yorker offered a useful education on the basics of "elevatoring":
There are two basic elevatoring metrics. One is handling capacity: your aim is to carry a certain percentage of the building’s population in five minutes. Thirteen per cent is a good target. The other is the interval, or frequency of service: the average round-trip time of one elevator, divided by the number of elevators. In an American office building, you want the interval to be below thirty seconds, and the average waiting time to be about sixty per cent of that. Any longer, and people get upset. In a residential building or a hotel, the tolerance goes up, but only by ten or twenty seconds. In the nineteen-sixties, many builders cheated a little—accepting, say, a thirty-four-second interval, and 11.5 per cent handling capacity—and came to regret it. Generally, England is over-elevatored; India is under-elevatored.
Fortune carries a “probable stop