Eyes on the Street: Bike Detectors Appear on 4th Street

Photo: Joe Anthony/Bike Commute News

Over the weekend, Bike Commute News’ Joe Anthony snapped this picture of brand new bike detectors for intersections on 4th Street between Mid-Town and Downtown Los Angeles. 4th Street has long been an important corridor for cyclists seeking to access Downtown Los Angeles from points west, but local opposition has stalled some of the more progressive treatments LADOT planned for the road. While negotiations between activists, LADOT and neighborhood groups continue, some features continue to be brought to the “4th Street Bike Boulevard.”

The censors have been in the street for a several months, it was the markings that are new, showing bicycles where they should position their bike if they want to trip the signal and get a green light.

  • Alex Boisvert

    Do these things actually work?  I’ve had (at best) mixed results with them in Santa Monica.

  • Alex Boisvert

    Do these things actually work?  I’ve had (at best) mixed results with them in Santa Monica.

  • First time viewing this blog, and really enjoy the currency/vibrancy that’s on it. I don’t bike, but I agree with the basic premise that the city has to be about its people at a very basic level. Thanks for this stimulating site.

  • I’ve had zero or mixed results with the 4th St. bike sensors in the past, but happy to report that last night they worked 100% of the time. The walk signal countdown began within seconds of stopping on the sensor, with no cars in sight. 

    I’m not sure if the sensors were fixed or adjusted in any way, or if the thanks goes to the markers for indicating how to use the sensors properly (with a wheel on each marker), but they do work! Hooray!

  • Joe B

    I complained about these not working to Santa Monica, and got back:

    “I spoke with our traffic signals staff and they indicate that we will be
    upgrading our software next week and bike detection will be repaired

    So, we’ll see.

  • Signal sensors on 4th were in fact adjusted recently, and again more recently, partly in response to survey and info gathered by LACBC’s 4th Street committee.

    Signal sensors are required to be able to detect bicycles in California, so if they don’tlet LADOT know!

  • My experience in Santa Monica has been that they don’t seem to be triggering the walk signal countdown for the cross-street any slower than when I’m at the same street in my car–I’ve used them on streets that cross major streets like SM Blvd or Wilshire, when even cars have to wait for a long time for the signal to change. 

  • Thanks Rick.  I’ve been on the mailing list so long I got my head turned around.

  • Those sensors do not appear to have been installed in the format decreed by state standards. The proper format is a rectangle with multiple wires crossing through it. The circle is intended for car-only lanes. 

  • Are the sensors in the ground, or are they video sensors mounted on the light signal, as in Santa Monica? 

  • Dan Gutierrez

    Quadracircle detectors like the one shown above a designed to detect bicycles and motorcycles.

  • Dan Gutierrez

    And to Jass, the quadracircle loop design does meet the limit line detection requirement in the CAMUTCD.   You are probably referring to type D loops as also meeting the requirement, however they are much more expensive to install and maintain, so they are not the first choice of many cities.  For example, Long Beach has been installing quadracircles since 2009 and the work very well.  This is the first time I’ve seen a quadracircle marked with the optional detector stencil.  Here are two slides I show Caltrans and Cities in the Understanding Bicycle Transportation course I teach to their staff on the subject of detection:



    FWIW, I was part of the team the helped the CTCDC define the standard, and here’s a presentation I put together before the new standard was adopted about loop detection:


  •  Thanks for the correction, I dont recall seeing this design in the CA MUTCD, or whatever the official document is that specifies what the sensors should look like. Sorry, it 3am, my memory is gone.