November 25


Sq lt
Notice anything different about the signal on the left?  Art Lebedev came up with this design which he details on his blog.  It uses square indications instead of round ones, which Art contends are easier to see and more aesthetically pleasing.  The round indications are a remnant of the first traffic signals that were created in the 1910's and 1920's.  Those original electrical signals were circles because they used light bulbs.  New indicatiosnNow we use LEDs and could easily switch to a different shape. 

A crazier idea – why do we need three indications stacked on top of each other (answer – it used to be for the color blind)???  Now that we have LEDs, we could put different indications in one spot.  We could combine the traditional colors with traditional shapes to reinforce the message.  This would reduce the size and cost of the signal indications, which in turn would allow us to use smaller metal poles which would save significant money.  Then we run them with solar panels and wifi saving cable and wiring…..

  • It is forward thinking such as this that moves us forward. I think there is merit to these ideas and applications. Remember that LEDs were controversial not too long ago.
    It is amazing that asking questions a 4 year-old would ask will get you everywhere!
    What is that?
    What does it do?
    Why is it done that way?
    It is the thought in the answers to these questions that makes the difference.
    Iteresting stuff, as always.

  • This is a tremendous idea, unfortunately I think the square is or rectangle symbol is a sign. The Traffic Signal shape and circle indications make a driver start to react just because of the shape. Alot goes on very quickly in your brain when you see a traffic light because we are trained from the time we get our drivers license to do something when we see that shape, even if there is no indication lit.

  • A redesign of traffic signal indications would need a lot of human factors testing to make sure we aren’t doing more harm than good. That said, dual left turn lanes and roundabouts both had significant naysayers in Minnesota. Dual lefts are commonplace (we are even up to a few triple lefts) in Minnesota. I suspect roundabouts will soon be commonplace too. I hope our industry keeps innovating and asking questions.

  • Mike,
    Interesting ideas using shapes to reinforce colors in traffic indications. I agree that it would take significant testing. In particular I would be concerned about the Octogon and circle appearing the same at night to a person who was colorblind without location on the signal head as a cue. Perhaps a variety of arrows could be used if the indication was large enough.
    Allentown, PA

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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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