09 August 2017

Crossing The Tracks

One of the invaluable life skills I learned in my youth is that of crossing railroad tracks on a bicycle.

If you've done it before, you know that you should approach them with your tire at a 90 degree angle--a.k.a. perpendicular (I remember that much from my geometry class!)--to the rails.  This is especially true if you are riding skinny road tires.


However, at many railroad intersections, this is not possible.  I have seen junctures where the road or path is nearly parallel to the rails when they meet.  Such intersections are all the more hazardous when, as often as not, the road or path has a sharp turn or curve just before it meets the tracks.  You then are faced with the same hazard presented by many urban bike lanes:  You are riding into the path of turning cars--at the same time you're negotiating the tracks.


So, perhaps, it's not surprising that in at least one locale, the most dangerous spot for cyclists is a railroad crossing.  


Knoxville, Tennessee is one such location.  Chris Cherry knows the spot all too well:  He watched his wife "really mangle her knee" after taking a spill at the Neyland Drive crossing.


Turns out, her mishap was one of 53 crashes recorded over a two-month period (2 August-3 October 2014) by a camera at the site.  As hazardous as railroad crossings are in general, this, city authorities acknowledged, is an unusually high number.


Cherry, an associate professor of engineering, at the University of Tennessee, decided to investigate.

 


  The problem was that the Drive crossed the tracks at a 45 degree angle--and, not surprisingly, the stretch of the drive leading to the tracks had a sharp curve.  

As a cyclist and engineer, Cherry knew that he best solution would have been to reconfigure the street so that it would cross the tracks at a right angle.  The city wasn't going to do that, however because the involvement of the groups it would have required--and the crossing's proximity to the Tennessee River--would have pushed the cost to $200,000.  Instead, the city used the "jughandle" approach (If you've cycled or driven on New Jersey State routes, you have seen it) to create a 60-degree angle.

Cherry, who was consulted on the project, knows it's not an ideal solution.  But, he hopes, it will reduce the number of crashes at the site.  So far, he thinks it's been effective.

Still, I think the intersection is one I'd approach with heightened caution:  I've pedaled through many others like it.

7 comments:

  1. Bad enough that the cyclists have not the sense to see danger at the tracks but it is a surprise that a bad knee is the only injury with cars constantly swerving to avoid killing the fallers!

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  2. Coline--It is scary to think she got "lucky" in "only" hurting her knee!

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  3. I have a brother in law who on his third shoulder surgery because of this very issue.

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  4. Phillip--Ouch! Crossing railroad tracks at too acute of an angle can indeed cause some of the nastiest spills!

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  5. Crossing RR tracks is more or less applied physics. One should go over the tracks at the best approximation to perpendicular under the circumstances. That means turning the bike a bit. We all know that you have to lean onto a turn and balance the centrifugal force wanting to make you go straight with gravitational force. (I have always felt like a bike falls around a corner.) The "fall" into a slightly more perpendicular path to the tracks lets you to glide over them. I notice that in the video the very first rider violates this principle: he turns into the tracks at first, but breaks off and goes straight instead of continuing his turn, and the second track grabs him. I would say that if you don't have room to make this turning maneuver, it is best to walk the bike over the tracks.

    Leo

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  6. Leo--All right, I confess: I have walked my bike over tracks when I couldn't cross at anything near a right angle.

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  7. Whatever happened to instinctively bunny hopping to avoid crashing into dangers in your path? My wheels have rarely been damaged...

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