Tuesday, July 27

Traffic Engineering Paradox

Basel Bike Facility Violates No Real Traffic Principles at this Turn Onto a One-Way Street
Some of the Signals Seem a Little Conflicted, However. I'll Bet Bike-on-Bike Collisions are Frequent

Europe is a mixed bag when it comes to cyclists. There are certainly a lot of bikes in the compact, congested cities. There are lots of special cycling facilities, ranging from pretty nice, to conflicted, to downright confusing things worthy of Warrington.

One of our building’s bike commuters, Sheila, just got back from visiting Europe, and she was kind enough to get a lot of cycling-related pictures. Today’s photos were shot in Zurich and Basel. As Sheila notes, it all seems to work, though a bicycle traffic engineer would recoil in horror.

This Poor Zurich Design Works Well Because Everyone Is Cautious Due to the Confusing Alignments
MOST of the Cyclists Ride Pretty Slow, Making it Easier for the Motorists to Miss Them

The variety of approaches reveals the paradox. Sometimes, dangerous facilities are safer, and safer ones are more dangerous. As a case in point, take Orlando, Florida. As noted in “Traffic” by Tom Vanderbilt, East Colonial Drive consists of two portions. One is the older portion. It has traffic conflicts galore. Poles, driveways, strip malls, the works. The other is the newer, “properly engineered” portion that removed the dangers in the older portion. Guess which one has overwhelmingly higher crashes and fatalities? Yup, the “safe” portion is one of the most dangerous roads in the US. Which one would I prefer to ride on? Yup, the “dangerous” portion would be my choice. Which one do people drive faster? You got it, the “safe” portion approaches Interstate speeds. Let’s just hope they don’t “fix” the “dangerous” part of the road.

I have no idea WHAT all this Nonsense is About - I Think This is Zurich

From Tom Vanderbilt’s book (Traffic: Why We Drive the Way We Do - and What It Says about Us), read about the Dr Jekyll/Mr Hyde personality of Orlando’s East Colonial Drive for yourself: here.

And so it is with bike facilities. With traffic congestion, lots of cyclists, and strict treatment of any motorist hitting one, the perceived danger in Zurich and Basel causes motorists to drive cautiously, and sometimes more around the worst facilities. It is one element that makes proper lane control of a narrow lane so safe, despite “feeling” suicidal –the motorist knows that bad things WILL happen without a proper lane change, and so they change lanes, mostly without even realizing it. As I said, it’s a paradox. Even small changes in the environment will cause motorist behavior changes, such as the addition of a sound barrier wall on a freeway, tunnels, or narrower lanes; which all cause motorists to slow down. The same principle achieves dramatic crash reductions in the “Shared Space” approach. Motorists actually HAVE to pay attention.
While I don’t advocate designing dangerous facilities to make users cautious, we should recognize that dangerous facilities are mostly dangerous to and from those too inexperienced, or clueless, to recognize them AS dangerous. The rest of us adjust our behavior to bring the risk back down. John Forester noted the necessary adjustment (either ride slowly and cautiously or take the longer street route and ride faster) when he considered Seattle’s Burke Gilman trail. As a cyclist, riding from point to point, my focus is with dealing with whatever facilities I encounter, as safely as I know how. My route selection is a balance that avoids danger while taking a direct route. As always, the winning combination includes experience, education, AND vigilance against complacency. Much as I hate to admit it, engineering has its limits.


cycler said...

To me the critical part of this is that drivers are held to a much much much higher standard of responsibility in europe. If you hit a vulnerable user it's automatically your fault, no matter what the bad street design is.
Unfortunately, I can't imagine that level of legal responsibility happening in our lifetimes in this country.

Chuck Davis said...

Pretty good post

As stated above the big biff here vs there is twixt the attitudes and numbers of those involved

There is always something lost or missing inspiration and execution and/or designing and engineering and the result is bound to be a compromise of varying degree

Chuck Davis, Tulsa

cafiend said...

I just bought Traffic, but haven't read it yet. BTW, anyone who thinks narrow lanes make people slow down hasn't driven much around Boston!

Ah well. We soldier on.

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