Want To Design Smarter Intersections? Use Less Control, Not More.
from the embrace-the-chaos dept
The topic of this post is sponsored by IBM. Read more about building a smarter planet on the IBM A Smarter Planet Blog. Of course, the content of this post consists entirely of the thoughts and opinions of the author and not of IBM.
Drivers in the United States are faced with a constant barrage of traffic signs, lights and signals all meant to navigate them safely through the sea of cars, pedestrians and bicycles without incident. Furthermore, US drivers are faced with an increasing array of laws that prohibit a multitude of things like speaking on the cell phone while driving, even though studies have shown that roads are not necessarily safer. Red light cameras have been installed under the guise of making intersections “safer,” even though, like the cell phone bans, study after study has shown that these cameras do little more than provide a revenue stream for the cities that employ them. The problem with using signs and fines to enforce driving behavior is that they usually attack the symptoms of bad driving, rather than the bad driving itself. After all, playing video games while driving has always been a bad idea, even before it was explicitly forbidden by law. Similarly, by teaching drivers to constantly monitor their speed and look out for red lights, they are preoccupied with the wrong things — they should be watching the road and traffic around them instead.
Instead of trying to micromanage every aspect of safe driving with signs, signals and laws, a better approach would be to utilize what should be the smartest part of the car — the driver. Just like a poorly designed door needs a sign to tell you whether or not to “push” or “pull” it, a poorly designed intersection needs to tell you when to stop or go. So, a better way to design an intersection seems counterintuitive: reduce the number of signs and signals. Back in 2003, in the Dutch town of Drachten, traffic engineer Hans Monderman replaced red light intersections with traffic roundabouts with reduced signage. Moving through the intersection, there are almost no signals or signs to direct the traffic at all. As a result, drivers, pedestrians and cyclists pay more heed to the actual traffic patterns within the circle. So, rather than blindly following traffic signals, they proceed much more carefully and make eye contact with each other as they make their way through the intersection. Traffic flows better now; gridlock is a rarity. Most importantly, six years after the improvements, Drachten is safer — prior to the roundabout, there were over eight accidents per year, after the roundabout was installed and traffic signs and signals removed, less than two. By making traffic seem more chaotic, it is actually made safer.
Of course, any new approach has its doubters — after all, intersections in Asia are infamously chaotic:
However, upon closer inspection, this seemingly chaotic traffic pattern actually works surprisingly well. Pedestrians, cyclists, cars and buses all coexist in relative chaotic harmony. With the addition on one simple rule, like a roundabout, it could possibly work even better — but, to try and control everything with traffic signals would definitely disrupt the flow. As our cities and towns get more and more congested, embracing this concept of “shared space” will become increasingly important. After all, traffic improvements aren’t just good for cars — they make cities more livable for pedestrians and cyclists too. Elsewhere, according to Wired, when the town of West Palm Beach converted “several wide thoroughfares into narrow two-way streets, traffic slowed so much that people felt it was safe to walk there. The increase in pedestrian traffic attracted new shops and apartment buildings.”
Recently, to celebrate 50 years of automobile safety improvements, the Insurance Institute for Highway Safety crashed a 2009 Chevy Malibu with a 1959 Chevy Bel Air. The results were impressive; the theoretical occupants of the 2009 vehicle would be able to walk away relatively unscathed compared to their unfortunate cohorts in the Bel Air. However, although modern autos do a great job of protecting vehicle occupants in case of an accident, a smart city with well-designed traffic systems could help to avoid such accidents in the first place.