Do traffic lights change for bicycles?
 

It seems that I have had to wait until a car pulls up behind me for the light to be triggered to change. It just doesn't notice bicycles. Has this happened to anyone else?
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Sometimes yes. Sometimes no. That why at least some states have laws that allow you to proceed against the red light if it won’t change.

Some do, some don't. I think they'll change for bikes more often now that we're overrun with intersection cameras and AI readers. I'm generally hesitant to stop then proceed through the red, even when it's clear, but I'm a big fan of the right turn / U turn / right turn method.

Majoritty of intersections have a pedestrian cross walk button which can speed up ligjt changes. It's no big deal to go and push one, I do it all the time.

My state has such a law, and I employ it occasionally when at a lightly-traveled intersection. Our stoplights don't seem to be tripped by a bicycle.

I don't necessarily agree with all the treatments or details depicted in the document, but this seems to be a good summary of bicyclist detection practice in the US:

https://nacto.org/wp-content/uploads...-Detection.pdf

The “Idaho Stop” law — allows bicyclists to treat STOP signs as a YEILD sign, and a RED LIGHT as a STOP sign.

Dan

Most in my area have sensors in the pavement and won't detect a bicycle. In low traffic I just proceed when it's clear.

If there are wires, it can help to position your bicycle right on the cut. There's one camera near me that only detects me if I'm turned partly sideways to present a wider target.

I position my bike directly over (inline) with one of these lines in the pavement and the light detects me every time.
Or you can hit the button for the pedestrians.


https://content.instructables.com/FN...bounds&frame=1

I have one intersection that I frequently ride through that has a camera. I need to stay in the middle of the lane for the camera to see me and change from red to green. If I stay over to the right, it doesn't pick me up.

I don't think that the intersections that use the in-pavement wire sensors will sense a carbon fiber bike.

I will run the red if I have waited through a couple of traffic signal cycles.

Traffic lights used to be almost all inductive loop sensors…wires buried under the pavement. If you can see the loop, those are easy to trip. This article details how to trip those. Finding the loop could be difficult after paving operations but if you can see the loop, riding directly over the wire will trip them. If the loop is a figure 8, the middle wire is doubled so it is most sensitive. Ride directly over the wire for as long as you can. See red lines in the picture below. The car in the picture is sitting on top of the left leg and thus has tripped the light but I can trip this light 100% of the time.
https://cimg1.ibsrv.net/gimg/bikefor...88ec69071.jpeg

The other sensor that has becoming more common is a motion sensor. They often look like a video camera on a stalk like the one below. These can be a bit more problematic because they are set to ignore small targets like pedestrians…wouldn’t want to trip the light every time someone walked by…but bicyclist are also small targets. Turning your bike sideways or waving your arms around in the air might trip them. But not always. If you do have one that is a problem, contact your local street division and ask for them to change the settings. If you can get 10 friends to call, so much the better.

https://cimg9.ibsrv.net/gimg/bikefor...268e9ed3b.jpeg

One thing to know is that every state has a provision for how to proceed if a light is malfunctioning. Wait for a reasonable amount of time…3 to 5 minutes…and proceed as if it is a stopsign being aware that the motorists don’t know that the light is malfunctioning for you. If you can’t get the light fixed, go over a block and cross at a stopsign.

+1
Carbon bike on Carbon wheels = a long wait.

Barry

Not necessarily. Carbon fiber is a conducting material and all that is needed to trip the circuit is a change in current caused by a conductor moving through the loop. Contact with the loop is key. Ride as much of it as possible with your wheel directly over the loop coil.

The sensor is an induction loop. Carbon doesn't change the induction as much as steel.

Barry

Do you ride in Fantasyville?

Just don’t forget that when riding in ID like I did the last time I was there. Waited a couple of minutes at a red light when there was no traffic in sight. Remembered where I was and had a good laugh at myself.

Operative word being “as much”. It still does. The inductive coil doesn’t need steel either. Aluminum trips them. It’s not the frame that does the work. There used to be an article “Detection of Bicycles by Quadrupole Loops at Demand-Actuated Traffic Signals by Steven Goodridge, Ph.D.” where he detailed how the wheels interact with the coil. Here’s a picture of his illustration of how the wheels interacts with the inductive loop. The website for the article no longer exists.

https://cimg2.ibsrv.net/gimg/bikefor...05bbdf6ed.jpeg

Carry a shovel with you. I once got into a restricted area that had card access only by taking a shovel out of the back of my vehicle and extending it over the fence to trigger the sensor loop in the pavement on the other side to open the gate for exiting traffic.

"steel exhibits powerful inductive properties, while carbon fiber is nearly inert. " < Clickable link

I've three bikes, all carbon.
Two are on carbon wheels, one is not.

Wanna guess which ONE trips the lights.

Barry

My bike (carbon frame, rims, spokes) will not trip any of the inductive loop sensors in the local area, including the ones exclusively placed to detect bicycles.

The camera sensors, on the other hand, detect me almost all the time.

There's a red light on my route that changes for me. I guess me and the bike are big enough to trigger the light. I ride early in the morning... so there's usually no traffic.

I've heard the detectors use magnets.. so chalk up a benefit for riding a steel bike :-)

I am not sure why you're trying to pick a fight, but to answer your question I ride in the suburbs, where 99% of intersections have a light change button that people can push. Some of these light change buttons are along bike routes so cyclists can use them too.

Most of the stop lights in my area include operating on a timer. They are not tripped by a car, nor do they change when pedestrians hit the crossing light buttons. It gets irritating in the off season when the traffic is lighter.
When I moved to Ocean City/Bethany beach, MD and DE, traffic lights were turned off from October 1 until May 1. Ocean City maybe had 500 year round residents on a 9 mile long and 4 block wide peninsula. I could ride my bike the whole strip, down and back, while seeing a half dozen cats, or less. The lights off was stopped in the early 80's due to the increase in full time residents.