December 22


Snow on LED Signal Indications – Low Tech Solution

By Mike Spack

December 22, 2016

CDOT, Colorado DOT, LED, minnesota, snow, traffic signal

In a past post I wrote about snow on traffic signal lights and how the light bulbs in older signals were warm enough to melt away snow that may land on the signal. The new LED lights used in many signals has a new challenge.  The LED lights are cool so, snow tends to stay on the signals. I thought I would share a solution that addresses this challenge. 

I came across a low tech solution sold by McCain (a large traffic signal supplier whose products are widely used in Minnesota).  Their Scoop Tunnel Visor has a beveled opening that provides air circulation around the LED lights which reduces snow build up.  They cost about $20 each (which isn’t much of an up-charge if they are being put on new signals instead of the standard visor).

Scoop visorThe Colorado Department of Transportation (CDOT) has been using the scoop visor and seems to think they work.  According to CDOT spokeswoman Mindy Crane – “They’ve helped immensely in terms of keeping the snow off the traffic lights.  It’s not high-tech and it’s very economical.”





  • An issue I’ve found with full visors — as opposed to cut-away visors — is when a signal goes into emergency flash. My city has a mix of red-red and red-yellow emergency flash patterns at different signals. I’ve found that full visors obscure the cross-street indications, which can result in confusion for motorists as they try to determine if the signal is operating in two-way or four-way stop control during the emergency.

  • FWIW, I tried the scoop visor when I was TE in a western SD city, and did not see any appreciable benefit during snow events. We tended to have the issue during events when the snow had a high moisture content, and winds were high, so YMMV. From what little I have seen, GE’s new heated inserts look like they are hardy snow-fighters, albeit at a much higher price & increased power consumption.

  • Like it a lot. As you may know, Winnipeg’s had some issues with our switchover to LED traffic lights; good to see a small-scale design change evolution that doesn’t entail additional heaters, etc.

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    Mike Spack

    My mission is to help traffic engineers, transportation planners, and other transportation professionals improve our world.

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