Thursday, October 20, 2011

I want to be traffic....well at least at the traffic light.

I decided this morning while waiting through a second round of traffic at a light....I was being ignored.  Not by drivers (they generally treat you well here in Reno), but by the traffic light (and maybe city engineers).  No cars arrived to save me from a third round of sitting in the bike lane, so I shuffled over to the pedestrian crossing to hit the button.  Needless to say I was on my way shortly thereafter.

Now this situation doesn't happen everywhere.  There are lights that are set on timers and regularly address traffic in all directions (and of all types).  The problem intersections have signals that are denoted by traffic engineers as "on demand" signals.  They can be triggered by several methods but the two most common are induction loops and cameras.  Most of the lights here in Reno use the induction loops.  You've probably seen them even if you didn't realized what they are.  At the intersection in each traffic lane you'll find very fine cuts in the pavement usually in the shape of a square or semi-circle.



Sometimes there not quite so obvious or they've been covered completely by recent slurry sealing, but this is the way many of the lights in town are configured.  They work by passing a continuous current through the loop creating an electromagnetic field of constant value.  When anything metal disrupts the field a sensor measuring the strength of the field is triggered and sends the light a message that says someone is waiting.  



So they don't work for bicycles!?  Not true, not true!  In many cases they do work for bicycles.  Traffic signal manufacturers will tell us that the metal content in our rims and crank arms are enough to trigger the sensors.  That is if the sensor has been calibrated properly and set to an appropriate detection limit.

The primary problem in the Reno area is that there are no sensors in the bike lanes (well, there is at least one in Sparks on Victorian ave.).  So, to trigger the light at this type of intersection your left with two options.  Move out of the bike lane and center a wheel over the induction loop (if you can see it) or do the "shuffle of shame" and hit the button for the pedestrian crossing.

There is hope however, crazy cities like Portland, Or and other top rated bike friendly cities are installing signal triggers in bike lanes.  Even Sparks has one...and it's marked  with it's own special marking!  So if you venture down Victorian Ave. keep and eye out for it and you too can be "traffic" in the eyes of a stop light!









 Official bicycle detector pavement markings symbol and a real life example (not the one on Victorian Ave.).









2 comments:

  1. This is good to know! I see these circles everywhere, and I just had faith that they were traffic detectors. I noticed if I stood too far in front of them, I wouldn't trigger the light. Now I stand right in the middle and I always get a light.

    "shuffle of shame". Ha ha. Yep, the straddle the top tube walk. Worse getting back to your spot in traffic and getting turned around!

    ReplyDelete
  2. The shuffle is even more fun with the xtracycle... I love the long bike but maneuvering is not it's strong point.

    ReplyDelete