Archive for February 2nd, 2009

One of my personal urban pet peeves is that the traffic signals on a street like New York’s Fifth Avenue, on which a majority of users are pedestrians, seemed timed in such a way to interfere as much as possible with smooth ambulatory progress. Seriously, I feel like I have to stop at every single light on Fifth.

From the invaluable Streetfilms comes a look at what would happen if a street like Valencia in San Francisco had its signals timed such that cyclists had a green wave. What about cars, you ask? Isn’t that anti-car-ism? Well, actually, as San Francisco Streetsblog points out: “Recently, the San Francisco Municipal Transportation Agency (MTA) found that during peak commute times vehicles run more efficiently when signals are timed at the speeds they actually travel during congestion — 12 to 15 mph — rather than the current 25 mph.” Not to mention that cyclist signal compliance rates will inevitably rise. On streets to which you’re trying to attract cycles, why not offer the carrot instead of merely the stick? Synchronization, in a grid city, has its natural limits but it’s certainly worth favoring certain modes on particular streets.

I often find some of the most hazardous urban driving behavior to be people accelerating between lights, or emerging from a pack of congestion. The question is how to get drivers to stick to speeds that are lower overall, but actually promote smoother, more fuel-efficient driving. ISA (intelligent speed adaptation) is probably the most far-reaching tool, but in some ways a political non-starter in the U.S. (for now, at least). I suspect that merely telling drivers through signage that the only way to get a row of greens is to drive 15 or 20 mph will somehow not work (the average driver is an incredibly opportunistic, short-range planner, only concerned with getting to the next red light as fast as possible).

Would you mind taking it a bit easy, mate? Photo by Kattaka/Flickr

One theme explored in the book is the usefulness of feedback to the driver, as well as the occasional unwillingness for a driver to want to hear this “feedback” (what we colloquially call ‘back-seat driving’). Some curious process occurs between man and machine by which they suddenly feel themselves above criticism, incapable of making an error, that they alone understand the road and traffic conditions. For anyone to suggest otherwise risks earning their wrath, despite the fact that studies have shown non-teen drivers with passengers are involved in fewer crashes than those flying solo.

A forthcoming study out of Kenya again hints at this dynamic. A pair of researchers at Georgetown University equipped a number of matatu buses, the private fleet of microbuses typical in many developing nations, with posters urging passengers to “heckle and chide” the driver if he is driving too recklessly. Rather like the recent hotline numbers at football games in which patrons can report drunken and abusive fans around them, the posters work on the idea that while everyone may be gripping the seat as the driver slaloms around town, no one individually feels empowered to speak up (a campaign in Ireland called “He Drives, She Dies,” urged a similar thing for female passengers in their boyfriend’s cars — it turns most who are killed or injured do so while passenger to a male driver; research apparently showed that most didn’t want to urge the driver to slow as they feared they would actually increase their speed if they did so).

The research — I’ll be posting again on the paper — apparently shows that buses in which the posters were displayed were involved in fewer crashes than those in which no posters were displayed (the buses account for some 20% of crashes in Kenya).

(Horn honk to Marginal Revolution and Shanta Devarjan)