On Seeing Red

John Allen

You may be waiting to cross a big street with heavy traffic. Or you may be waiting in a left turn lane. The traffic light is red as you approach.. Then the traffic signals go through an entire cycle, but they skip the one that applies to you.

This is a safety issue. Why does this happen, and what are you to do?

This isn’t the first time I have written about the problem. I had an article in the October 2013 WheelPeople, accompanying a video,

The video shows CRW members, waiting, and not waiting, for a traffic signal on Boylston Street on the Climb to the Clouds Ride


I think that it is fair to repeat the content of the article here, because little has changed. So here goes, lightly updated.


Most people on CRW rides know how to turn left (just as motorists do) – first merging to the left-turn position on the roadway. Everyone in this video I shot during the July (2013) Climb to the Clouds ride did that. 

The left turns on red shown in the video are by no means entirely the bicyclists’ fault. The left-turn signal is triggered by a metal detector buried in the roadway, which in this case did not detect bicycles. The bicyclists who ran the red did wait -- but when the signal did not change, they lost patience.

Still, if the bicyclists had known to line up carefully over the pavement cuts that indicate the locations of the detector wires, the signal probably would have changed.

A motorist was waiting behind the bicyclists, but too far back to trigger the signal actuator. The motorist appeared to be staying out of the way of the group of waiting bicyclists -- and waited through an entire extra light cycle. Perhaps the motorist was trying to be considerate.  On the other hand, the motorist could have resolved the situation without anyone’s running the light, by pulling forward over the detector –and probably didn’t know that.  After the first group of bicyclists left, I motioned to the motorist to pull forward, and the light did change. The remaining bicyclists then proceeded on a green signal.

But he most effective time for a teachable moment about signal detectors isn’t while waiting in a group of bicyclists who are arriving at random. Even more so for a motorist, who is out of earshot inside a vehicle. My failed attempt in the video demonstrates that well enough.

So, what can you do to help?

If you are a ride leader, be aware of these issues on your route. You can discuss them briefly in the pre-ride talk. More effective is to improve on the generic bare-bones cues in RidewithGPS. Your cue could, for example, say “form a double line in the left-turn lane, with your wheels over the wire cuts.”  Traffic-signal troubles are only one of several reasons to check and revise RidewithGPS cues.  They often come too late to allow correct preparation for a turn, and sometimes they are simply wrong.

If you ride a Club route on your own, alert the names ride leader to problem spots.

Spread the knowledge of how to trigger signal actuators when talking with other cyclists

Develop a culture of orderly assembly when queuing at intersections. This includes not only avoiding sloppy, risky moves like the close passes of a moving motor vehicle shown in the video, but also stopping in a neat formation over the wires of the metal detector loops.  An orderly group also might encourage motorists to feel more comfortable in pulling forward to help trip signal actuators.

A final point about neatness.  Note the motorcyclists in the video. Both bicyclists and motorcyclists have problems with public image, but the motorcyclists in the video were doing a fine job of dispelling their image problem. Even if bicyclists must proceed on red, orderly appearance conveys a more positive message than the ragged group of bicyclists in the video.


End of the 2013 article. But let me take this discussion a bit further.

The Massachusetts Department of Transportation has been fairly good about installing bicycle-sensitive actuators. Some cities and towns also have been, notably Watertown. When main streets are state highways, often the signal installations are by MassDOT.

But In 1989 I sent a polite letter to the traffic director of the City of Waltham, where resided then – and still do now.  I described the problem of traffic signal actuators that do not turn the light green. In 1991 I sent a less polite letter. And I have raised the issue several times since.

Now in 2022, the City of Waltham constructing a section of the Mass Central Rail Trail. And repaving a number of streets. I’m all in favor of both of those initiatives.

But I rode a couple of those recently repaved streets last week and Waltham still is laying the wires for its traffic signal actuators in a pattern which does not detect bicycles and motorcycles. We have the frosting, so to speak, but no cake.

Perhaps in the light of the millions of dollars of local and state funding that the City of Waltham is spending on these projects, I’ll finally be able to shame city officials into laying the wires in a different pattern in the street next time. (That’s all it takes -- it costs nothing.).

The city might consider its Complete Streets policy, to wit:

 In the City of Waltham, Massachusetts, Complete Streets are designed, operated, maintained and enforced to provide safety and accessibility for ALL users of our roadways, including pedestrians, bicyclists, motorists and transit users of all ages and abilities.

And please also look into this issue in your own community!



John, This issue is one of my pet peeves. The infamous intersection you profiled is not unique. In fact, I don't think I've ever successfully triggered a traffic light when riding solo without the help of a nearby car or a larger group. As you described, if a bicyclist stands on the bike-icon over the sensor then cars typically stay too far back to trigger the sensor. I also think the sensor placement for bikes should go across the entire lane not just in the middle. The middle position is only used by bikes turning left. The normal position for a bike is on the right side of the lane where the bike sensor definitely won't detect you. So who do we complain to in the state Gov't? There are thousands of these sensors all over Mass roads and basically none of them work. I doubt this would be tolerated for motor vehicle traffic.