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.”