Which half? One day when I was a junior medical student, a very important Boston surgeon visited the school and delivered a great treatise on a large number of patients who had undergone successful operations for vascular reconstruction. At the end of the lecture, a young student at the back of the room timidly asked, "Do you have any controls?" Well the great surgeon drew himself up to his full height, hit the desk, and said, "Do you mean did I not operate on half of the patients?" The hall grew very quiet then. The voice at the back of the room hesitantly replied, "Yes, that's what I had in mind." Then the visitor's fist really came down as he thundered, "Of course not. That would have doomed half of them to their death!" God, it was quiet then, and one could scarcely hear the small voice ask, "Which half?" E.E. Peacock Jr., Seeing With Fresh Eyes science
Induced demand Every attempt to cul-de-sac city streets, to change traffic patterns in favor of pedestrians, or to narrow street ends is met with the same howl of protest from the authorities: this will increase congestion because urban traffic is a zero-sum game. Any reduction in volume in one place in the city will inevitably be accompanied by a rise in traffic somewhere else. This claim is fallacious: the true corollary is the opposite. In case after case, a reduction of the space available for vehicular traffic has simply resulted in the reduction of traffic overall. Michael Sorkin, 20 Minutes in Manhattan Like trying to cure obesity by loosening your belt transportation