Sometimes motorcycles trigger the turn signals, sometimes they don’t. What gives? Just ask Jeff and McRider.

Question: Why don’t left turn arrows turn green for motorcycles alone in the left turn lane? Will a long overdue fix ever come? It usually happens to me late at night, or whenever I am alone in the left turn lane, the arrow does not change to green. Some examples: College Ave & Morgan St., Guerneville Rd & Marlow Rd., Guerneville Rd & Coffey Lane. — Jeff

Answer:  Those locations are camera detections, which typically do a great job of detecting motorcycles, said Rob Sprinkle, Santa Rosa traffic engineer.  It may be the signal cycle that seems long, and lefts and side streets will take a little longer to be served.  It may not be that the car comes behind to trigger the signal but that the signal cycle is long. So a car has time to come up behind and it seems like that is the issue.

“We are working to shorten cycle lengths to get the signals to be more responsive in off-peak times,” Sprinkle said. ” That work should help the most. We will review those locations and verify motorcycles are being picked up.”

Question: Rohnert Park has a big problem when it comes to Lights and Motorcycles too! just over half of them never detect Motorcycles waiting “Please fix”… especially the one coming out of Costco to make a left turn from Marton to redwood drive!… — McRider

Answer: ”I checked with Public Works and this is the first we have heard of a problem at this light.  We will have it checked out,” said Patrick Barnes, Rohnert Park’s deputy city engineer.

There are different triggering mechanisms for lights.  Some are video detection, but most of the older signals and any Caltrans installed signals have loops in the pavement that detect steel.

For a motorcycle, depending on the size, it may help to get toward the side of a loop rather than in the middle of it.  Generally a loop will not pick up a bicycle. Barnes said, “This is one reason we are moving towards video detection where it is practical.”

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  1. Tim

    I wait, and if I determine the light isn’t triggered, Just wait until it’s clear, then when safe to do so…bye bye. If it never clears, I’ll turn right and make a u-turn when legal. Happens only occasionally, especially rural areas.

    June 6th, 2013 7:10 am

  2. Driver

    Whenever a faulty sensor is found it should be reported. The city workers are understaffed and don’t have time to check everything all the time. Public input is valuable for all repairs and hazards on the roads. Use your input to get things done!

    June 6th, 2013 9:42 am

  3. jeff

    So it just “seems long”? After the light has gone through 3 complete cycles and no left turn arrow, you bet it “seems long”. That’s because it IS long. Sorry, but that’s a non-answer.

    June 6th, 2013 9:47 am


    Riding up to the pedestrian crossing button sometimes helps while going straight across but those left turn lanes, the lone biker may fall asleep waiting for a green arrow.

    June 6th, 2013 12:18 pm

  5. G

    “Some are video detection, but most of the older signals and any Caltrans installed signals have loops in the pavement that detect steel.”…This is the main problem for motorcyclists, as motorcycles these days have very little steel, if any, and are mostly made up of non-ferrous metal like aluminim and other alloys.

    June 6th, 2013 1:03 pm

  6. G

    Aluminum, not aluminim…ugh

    June 6th, 2013 1:04 pm

  7. Robert Collins

    What is a motorcyclist or bicyclist to do if they want to make a left turn at a light that does not change because the sensor does not pick us up? Can we go when the traffic is clear?

    June 6th, 2013 2:16 pm

  8. LeeRoy

    The Left Turn from east bound 3rd onto B Street doesn’t always like motorcycles either. Thats coming up the dip that goes under the Mall.
    Usually there is enough traffic a car comes up to be detected.
    Curious if waving hands at the Cameras will assist in detection?

    June 6th, 2013 2:18 pm

  9. Heywood Jablome

    I have ridden for many years and find that if I approach the intersection slowly and hang back a few feet I get the light to trip almost immediately and every time! NICE.

    June 6th, 2013 3:51 pm

  10. Wendy

    The questions are not rants, but are logical, clear and concise. The answers provided don’t offer real solutions, however. I’d like to see a follow-up to this Q&A session by someone willing to put more effort into really looking into the problems and suggesting solutions.

    June 6th, 2013 9:50 pm

  11. x

    just another example of how pointless left turn lanes are . make it “right”, replace them all with traffic circles.

    June 12th, 2013 6:47 pm

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