Advocacy & Safety - Ticketing

I just picked up a new road bike that I have been using for commuting. I understand i have to follow the same laws as passenger vehicles, however, I've had to wait for minutes waiting for lights to change due to inability to trip the sensor. How are most people dealing with this issue?

Also, if I'm ticketed for running a stop sign or other traffic violation, will it show up on my driving record?

Thanks,
Sam

Legally, get off the bike and walk it across the street.
practically, make the dash after looking every which way.

Legally, if the sensor for the light does not detect a bicycle, then it is defective. Contact the proper DOT and ask them to adjust the detector sensitivity.

Until then, if the sensor does not work, you can legally treat the light as a stop sign.

Until then, if the sensor does not work, you can legally treat the light as a stop sign.
You may want to check with the local laws on that one.

And in most states (I think all, but I'm not a lawyer), a ticket on your bicycle cannot legally show up on your driving record. After all, you don't need a driver's license to ride a bicycle ;)

I've learned how to trip the ones on most of my regular routes. Look for the "seam" in the road, usually in the shape of rectangles. This is where the sensor wires are. When approaching the light, slow down, and ride right along the seam. This is what works for me. There is one that does not respond to this technique though, at the intersection of Ward street and Center street, Newton MA. This is especially annoying, as there is always plenty of motor vehicle traffic on Center, but typically very little on Ward. This technique takes some practice.

On your second question: While you are not legally required to carry a driver's license on you while cycling, some PO's tend to get agitated when they demand ID, and you produce something other than a license, such as a work ID or student ID. (i.e. "Don't you have a license on you??") Best to check with local cycling advocacy groups about this question, or better yet, an attorney that is concerned about cyclists' rights.

Traffic light sensors are actually metal detectors. They detect ferrous metals - that is, steel. If you have an aluminum or carbon fiber frame, it is unlikely you will be "seen" by the sensor. That is one reason I prefer steel bikes.

If you look at the ground in the traffic lanes where cars stop waiting for the light, you will likely see where the surface has been cut in the form of a pair of long rectangles next to each other. Underneath it is a figure eight of wire that forms the sensor of the metal detector. I have found that by placing my bike on the middle line (where the boxes are joined), up about where the "T" is formed closest to the cross walk, I can generally trip the light.

As for your second question "Also, if I'm ticketed for running a stop sign or other traffic violation, will it show up on my driving record?"

The answer is, if the ID you present to the officer is your driving license, yes. Around here (Tempe / Phoenix Arizona) cyclists are given a fair amount of latitude. One thing that the Tempe police do frown on is riding the wrong way on the sidewalk near the Arizona State University campus. I say bravo - that is a bad practice, and very dangerous for the rider.

On your second question: While you are not legally required to carry a driver's license on you while cycling, some PO's tend to get agitated when they demand ID, and you produce something other than a license, such as a work ID or student ID. (i.e. "Don't you have a license on you??") Best to check with local cycling advocacy groups about this question, or better yet, an attorney that is concerned about cyclists' rights.

You beat me to the first part...

Agreed on the PO agitation - but since you are not required to carry your license except when driving, I don't see where they can force it. I think the issue is that the computer systems the cruisers are linked to do a quick and easy look up on licenses - saves the officer a lot of work. Other ID types require mechanical work on their part. I have thought about getting a passport card for just that reason.

Traffic light sensors are actually metal detectors. They detect ferrous metals - that is, steel. If you have an aluminum or carbon fiber frame, it is unlikely you will be "seen" by the sensor. That is one reason I prefer steel bikes.
Actually, they work off of an induction current, and will detect anything conducts electricity. An Aluminum frame works just as well as a steel frame.

If you have a carbon frame, well, guess you're SOL. :lol:

Actually, they work off of an induction current, and will detect anything conducts electricity. An Aluminum frame works just as well as a steel frame.


True. they are an inductor as one leg of a wheatstone bridge, but Iron has a much bigger impact on the inductance change in the inductive loop. So while "technically" an aluminun frame can trip them, my experience has been that steel is much more likely to succesfully trip it. But then I am picking nits...

So while "technically" an aluminun frame can trip them, my experience has been that steel is much more likely to succesfully trip it. But then I am picking nits...

And my experience has been that my Aluminum frame trips all of the stop lights I ride by. There was one that didn't work, called the local DOT, they came out and recalibrated it, now it works.

They all can be made to trip for an aluminum frame. If you ride by one that doesn't trip, call and have it adjusted.

Here is the applicable Virginia statute:


§ 46.2-833. Traffic lights; penalty.

...


B. If the traffic lights controlling an intersection are out of service because of a power failure or other event that prevents the giving of signals by the traffic lights, the drivers of vehicles approaching such an intersection shall proceed as though such intersection were controlled by a stop sign on all approaches. ....

If the sensor doesn't trip, you can always hit the crosswalk button

My experience is that most lights will operate for a bicycle, you just have to figure out where and what to do to get the light to operate.

If the sensor doesn't trip, you can always hit the crosswalk button
Not really. Many intersections have no crosswalk buttons. Furthermore the times when I've most frequently had issues with the sensors has been in left turn lanes and any crosswalk buttons do not trip the left turn arrow nor is it technically legal to jaywalk against the light to even reach the sidewalk.

I agree with the previous advice to treat a non-responding light as being defective and therefore treat it as equivalent to a stop sign. Also report it to the appropriate traffic agency so they can adjust the sensitivity. At the frequencies used by the inductive sensors aluminum is just as effective at tripping them as steel and most carbon fiber bikes still have aluminum rims which should be sufficient if the sensitivity is adjusted properly.

When a transportation department is really trying to adjust a light sensor to work properly (ie: including for bicycles) they will often times just use a front wheel from a bike as their test subject. They should trip just fine off an aluminum wheel sitting above the sensor wire.

That said... as others have noted, in general the proper way to handle a light that will not change is to wait for at least a full cycle then proceed when safe (ie: treat it as a stop sign)

As for your second question "Also, if I'm ticketed for running a stop sign or other traffic violation, will it show up on my driving record?"

The answer is, if the ID you present to the officer is your driving license, yes. Around here (Tempe / Phoenix Arizona) cyclists are given a fair amount of latitude. One thing that the Tempe police do frown on is riding the wrong way on the sidewalk near the Arizona State University campus. I say bravo - that is a bad practice, and very dangerous for the rider.

It may or may not show up on your driving record. What you care about is whether it's going to effect your insurance. The answer for that is that you'd better check your state laws. In Massachusetts violations made while on a bicycle do not effect safe driver status for automobile insurance. It doesn't matter what ID you show the police.

Speedo

Actually, they work off of an induction current, and will detect anything conducts electricity. An Aluminum frame works just as well as a steel frame.

If you have a carbon frame, well, guess you're SOL. :lol:

The last time I checked, carbon fibre was a good conductor of electricity.

Because induction falls off rapidly with distance, a traffic signal trigger sensor is affected far more by your rims than by any other part of your bike. If I stop with both tire contact points right on the loop detector, I can generally trigger the light. My biggest problems arise when repaving renders the loops invisible.

The best thing to do would be to call the local police and ask the shift supervisor what you should do. They are the ones that would write you a ticket.

In NC, as of Jan 1, 09, it's legal for motorcycles and bicycles to treat lights like stop signs if they won't change. I've been doing this for years with no probs anyway. :thumb:

Most states have something in the law to guide road users on what do do if a signal does not work for them. Usually, it is some variation of coming to a complete stop, waiting for the specified period of time, then proceeding when it is safe to do so.

As for ID while riding, keep in mind that signing a ticket, and being allowed to go on your way, is, in effect, a PR bond on your part. An officer may require a detained person, even a pedestrian, to identify himself with an official form of ID, and may not be satisfied with student or work ID. The officer may be required, in fact, to write the number and issuing entity on the ticket or on his other paperwork. If ID cannot be established, the detained person may be required to post a bond, or be held for a judge to deal with. I don't want to take this thread off onto that tangent; it deserves its own thread, or perhaps one of the previous threads on that subject can be resurrected. Just to be clear, while I am opposed to being REQUIRED to carry official ID, I darn well do so, for very practical reasons. If nothing else, if I fall, and bump my head, or die, it makes things SO MUCH easier for officialdom AND my next of kin if I am carrying official ID.

A trick I found a while ago is to gently lay your bike down after getting off. Laying your bike down directly atop the detection loops maximizes the metal that is involved with the loop, and will usually set it off. (All of this assumes that you're riding a metal bike, of course.)

A trick I found a while ago is to gently lay your bike down after getting off. Laying your bike down directly atop the detection loops maximizes the metal that is involved with the loop, and will usually set it off. (All of this assumes that you're riding a metal bike, of course.)


Ah.... Finally I can claim all those 0 MPH clipless falls were intentional.....:lol:

Put two rare earth magnets on the bottom of your bike. You should be able to pick some up for a few dollars at a local electronics store (e.g. Radioshack). Many motorcycles have some of the same problems, that is how they solve it with them.

Put two rare earth magnets on the bottom of your bike. You should be able to pick some up for a few dollars at a local electronics store (e.g. Radioshack). Many motorcycles have some of the same problems, that is how they solve it with them.

That will do absolutely nothing. The loops work off of an inductance field and not a magnetic field.

The last time I checked, carbon fibre was a good conductor of electricity.

Really? Had no clue. Makes sense if they interleave the carbon with some sort of metal.

Really? Had no clue. Makes sense if they interleave the carbon with some sort of metal.
No need to, CF itself is a good conductor.
... As a result of the high conductivity of the carbon fibres it is assumed ...Link (http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWT-4319NKM-2&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=7b0affbb576cf29ad104f06824de0c1a)

No need to, CF itself is a good conductor.
But the inductive sensors depend on their fields creating a current in the detected material. The individual carbon fibers are reasonable conductors (although I don't think they approach regular metals), but a bike frame is made of separate fiber mats bonded together and I wouldn't expect them to be connected together electrically - i.e. individual fibers are probably going to be separated by insulating bonding material. Therefore the sensor won't set up a current around the loop of a carbon frame the way it would with a steel, titanium, or aluminum one.

However, as mentioned before, all that's needed for detection by a properly sensitive detector is a metal rim.

If you have a carbon frame, well, guess you're SOL. :lol:
If you have a carbon frame you're probably not stopping anyway... http://img61.photobucket.com/albums/v185/MemoryLane/bolt.gif

A carbon frame should be no problem, because it is primarily the bottoms of your rims that the sensor "sees." The guys with carbon rims are probably SOL, but I am not convinced that carbon rims are as safe and reliable as metal rims, anyway.

You may want to check with the local laws on that one.

I basically agree with CB HI on that one but I will note that while how to treat a defective signal is a mater of law but using that as a defense is a court of law is just that, a defense.


The best thing to do would be to call the local police and ask the shift supervisor what you should do. They are the ones that would write you a ticket.

No the shift operator does not write the ticket and is not an authority on bicycle law unless they have gone through officially recognized training. You are within your rights to request an officer trained in bicycle laws to make the judgment call. But if you do this at time of a potential ticket, human nature is such you may offend the arresting officer and they will throw the book at you.

That will do absolutely nothing. The loops work off of an inductance field and not a magnetic field.
There is no such thing as an inductance field. There are magnetic fields, and electric fields. Traffic signal sensors use coils (inductors) embedded in the road. Inductors generate magnetic fields, as do the permanent magnets used by motorcyclists. The sensors detect a change to the magnetic field generated by the coil in the road. I'm still not sure a permanent magnet would have any effect on a light sensor, because the sensor could be using an AC (alternating current) magnetic field, in which case the permanent magnet would be useless.

I should've prefaced what I said with, I barely passed Physics 2 (E&M), so I am a lot of times full of it. :o

Actuated signals, as presently implemented, do not work well for bicyclists. I will sometimes go out of my way to avoid one. At other times I do the stop and go. There is one intersection where I go when the light turns green for opposite direction traffic (on the same road that I'm on), even though I still have a red.

I've had excellent success with some detectors (mostly quadrupole types) and little to no success with other detectors.

Detector loops work on alternating current (an inductor is smiply a short circuit to DC).

My understanding is: AC applied to the coil creates an electro-magnetic field, which will induce a current in any good conductor, say, the rim of a bicycle wheel. The current in the wheel creates it's own electro-magnetic field, which opposes the field of the sensor coil and changes the inductance of the sensor coil. This change in inductance can then be detected by the circuity as a change in frequency of the AC current.

An aluminum bicycle wheel works well but the curcuit has to be adjusted to much greater sensitivity than what is needed to detect an automobile (this greater sensitivity could possibly lead to false positives caused by say, an automobile in an adjacent lane).

The bicycle wheel also needs to be placed in the right place over the sensor. The "sweet spot" is different for different coil patterns (in the center for quadrupoles and at the edge for most other types). If the bicycle is in the wrong place, detection will fail even though the sensor is adjusted to detect bicycles. This is a major problem since hardly any bicyclists recognize the different patterns and can identify the sweet spot. Bicyclists shouldn't have to do this anyway. Getting a light to work shouldn't be a puzzle.

A good article by Steve Goodridge on how these things work:
http://www.humantransport.org/bicycledriving/library/signals/detection.htm

(this greater sensitivity could possibly lead to false positives caused by say, an automobile in an adjacent lane).

We had a traffic engineer use this as the reason why they could not adjust the sensor for bikes so I asked why false positives are bad and false negatives are good. That was fun watching him try to back out of that one.

I basically agree with CB HI on that one but I will note that while how to treat a defective signal is a mater of law but using that as a defense is a court of law is just that, a defense.



No the shift operator does not write the ticket and is not an authority on bicycle law unless they have gone through officially recognized training. You are within your rights to request an officer trained in bicycle laws to make the judgment call. But if you do this at time of a potential ticket, human nature is such you may offend the arresting officer and they will throw the book at you.

So, you just go looking around for something in the laws then guess if you or the police officer is going to be correct? Have fun taking time off to go work all that out in court. I was suggesting that the OP call the person in charge of all the traffic officers in his/her area and ask about it ahead of time. Get a determination from the people that would be writing the ticket.

So, you just go looking around for something in the laws then guess if you or the police officer is going to be correct? Have fun taking time off to go work all that out in court. I was suggesting that the OP call the person in charge of all the traffic officers in his/her area and ask about it ahead of time. Get a determination from the people that would be writing the ticket.

I was not questing the value of getting the information ahead of time just clarifying who someone should talk to to get an informed response and I was cautioning using that line of query at the time of the accident. I will also note that bicycling advocacy groups can advise police on the proper enforcement of laws.