Urban traffic engineering

James’ post about the Oxford Circus redesign fails to distinguish three very different ideas about managing movement in urban spaces, though if you follow his links you can parse it out.

The culture of traffic engineering is about moving cars (in parts of Europe, bicycles and trams also) quickly, and one of its tropes - James’ main target - is to get the damn pedestrians out of the way. Also the bicycles, in most of the US until quite recently: the Secretary of Transportation of Massachusetts said to me in 1981, when I asked what programs he was planning for bicycle commuting, “well, they mostly just interfere with traffic, right?”.   This leads to fences along curbs to prevent jaywalking and funnel pedestrians to approved crossing lanes, and some really appalling things like the two-story stair climb required to cross the eje’s (arterial through streets) on which Mexico City drivers drive park in ranks and files during rush hours, not to mention the quarter-mile hike along the eje to get to one.

The first big idea is the realization that cities are not about being easy to drive cars through; cities are about being easy to get about in by many modes, especially including feet (and wheelchairs), and having places that are nice to dawdle in.  Respect for modes other than cars has led to some quite amazing engineering, like the four completely separated  interlocking, light-controlled systems for pedestrians, bikes, cars and trams in the Netherlands.

The second idea is a fairly modest innovation, called the Barnes Dance when introduced in New York by Henry Barnes, the traffic commissioner: this is the four-way red for cars at orthogonal intersections and free pedestrian movement between any two corners.  It turned out to slow vehicle traffic very little and greatly eased walking; this is the idea introduced at Oxford Circus, where allowing people to walk in the direction they want to go allowed the removal of a bunch of fences and street junk.

The third idea is genuinely revolutionary.  Hans Monderman, one of my heroes, was the  champion of the astonishing idea that a lot of busy, complicated urban spaces work better for everyone if cleared of traffic lights, sidewalks, curbs, and crossing controls and turned into a free-for all (I also have to admire the courage of the elected officials who let him try this the first time).  It turns out that when they aren’t dependent on lights and lanes, and know that the right-of-way is full of pedestrians, bikes, and hot-dog wagons, drivers slow down, take care, and (this is one remarkable outcome) get through the space faster. Pedestrians step out of the way of the cars with modest inconvenience, and (this is the other remarkable outcome) accidents, including pedestrian accidents fall substantially. Obviously, there is an inescapable tradeoff between pedestrian and car convenience, and between safety and convenience, but these are two more of the many obvious things that are also false.

The recognition that behavior is not always improved by formal controls, but often by transferring decisionmaking back to people who can efficiently size up situations and will generally be polite and cautious, is quite important and much bigger than street  design.  In my business, to mention only one example, a lot of my colleagues seem engaged in a losing arms race with their students to control cheating by what seem to me to be infantilizing rules, requiring them to put their backpacks on the floor at the front of the room during exams, not letting them come back in the room if they go to the bathroom, and the like.  That kind of thing really grates on me; I don’t see how I can expect students to act like grownups if I treat them like children, much less juvenile delinquents.  It’s possible I’m being cheated blind, but I’m pretty sure I do better giving only open-book, open-notes midterms (this helps them not obsessively memorize stuff) that are all  essay questions (for which I tell them, stuff they bring along probably won’t be useful but might be comforting), but nothing electronic allowed.   They also grade each other on class participation, so I can expect a certain amount of peer control for which I don’t have to play Mommy; presumably most students will be inhibited about being seen to cheat by exactly the people they are cutting in line ahead of, and who will be registering consequential judgments about them.