traffic signal actuators

[mimitabby]

this is true in Seattle; not sure about where you live:

"As far as bicycle detection is concerned, I suggest that you center the bicycle in the center of the lane with the front wheel approximately 2 feet from the stop bar or crosswalk bar. If you have a particular intersection that does not seem to "see" you, I would like to know about that as well. We are often able to change the sensitivity of the detector to help better detect bicycles.”

I received this information from a city streets employee.

oh, and hey, on some of them, it works.

If any of you seattle people know of a bad actuator, PM me and i'll give you the lady's email and contact info

[Thorn]

Most major cities and/or counties have a similar contact person. Our local contact was so helpful he managed to get a light just outside of his jurisdiction adjusted.

In Wisconsin we have a 45-second rule (might be 30-seconds, but I give it 45just to be safe). If a motorcycle or bicycle is at a signal-controlled intersection without any motor vehicles to trip the switch and they have waited 45 seconds, we can legally run the red light.

However, the intersection I reported has 55mph traffic (posted speed limit, so you know they're going faster) on a curved road with a slight hill to make visibility even worse. I requested that the sensors be adjusted and now have no trouble getting the light to switch. Much nicer. Take the time--it is worth it.

[JaneE]

Gee, I never knew this was even possible!

We live in a semi-rural area with a number of intersections with this types of signal control (as well as 55 mph speed limits). When there are reasonable breaks in traffic we've been known to, on occasion...ahem...run the red light. Otherwise you could sit there until H*ll froze over waiting for the green light if another car didn't happen along.

I will definitely pursue this. Thanks!

[OakLeaf]

There are two types of signal actuators: the new optical ones (lives on top of the light, and looks similar to a red-light camera), and the old magnetic ones. I'm pretty sure it's impossible to trigger a magnetic actuator unless you have a steel frame. Traffic authorities are supposed to adjust the sensitivity of the actuators, but they're not going to replace their whole system.

I'd give it longer than 45 seconds, too, many lights have a longer cycle than that!

Also, if you're at an intersection that has some traffic so there's a car behind you, pull way up so that they can trigger the light. A lot of times cars hesitate to get too close, so beckon, and holler at them if they don't get the message!

[kelownagirl]

I wonder if that works here too? Ours are magnetic... We usually have to go over and push the cross walk signal to get the light to change. If there's no traffic, I sometimes run the red....

[mimitabby]

Also, if you're at an intersection that has some traffic so there's a car behind you, pull way up so that they can trigger the light. A lot of times cars hesitate to get too close, so beckon, and holler at them if they don't get the message!

I used to do this too, just pull up way forward IN CASE a car would come, as well as staying to the far side of the lane, so i would miss the actuator!!

now i just go right for the center of the lane and IT WORKS! (but not all intersections)

[Eden]

There are two types of signal actuators: the new optical ones (lives on top of the light, and looks similar to a red-light camera), and the old magnetic ones. I'm pretty sure it's impossible to trigger a magnetic actuator unless you have a steel frame.

This is a common misconception, but the buried type of traffic detectors use induction (similar to a metal detector), not magnetism or weight. Any type of metal will set off an induction loop, so an aluminum or ti frame should set one off just as easily as a steel one (I suppose if you could drag around a bike made of gold that would work too ) . Even a CF bike, if it has metal rims/spokes will set trigger a traffic light that is set up to be sensitive enough.

If you can see the cut out in the road the best place to position yourself is along the edge of the cutout, front wheel angled along the top of the cutout, the whole bike leaned a bit into the loop. Basically making the metal parts of your bike look as big as possible to the detector.

[Pax]

I had a guy on a motorcycling forum suggest a strip of rare earth magnets sandwiched between two strips of electrical tape. I put it on with zip ties and it works like a charm.

[mimitabby]

oh yeah, and a bike buddy of mine told me that he saw a Seattle traffic engineer working at an intersection with a bike wheel in hand, checking the actuator!

[kfergos]

This is a common misconception, but the buried type of traffic detectors use induction (similar to a metal detector), not magnetism or weight. Any type of metal will set off an induction loop, so an aluminum or ti frame should set one off just as easily as a steel one (I suppose if you could drag around a bike made of gold that would work too ) . Even a CF bike, if it has metal rims/spokes will set trigger a traffic light that is set up to be sensitive enough.

Huh. I have a light I go through that recognizes me on my steel bike, but never on the aluminum one.

Speaking of solid gold bikes: http://living.oneindia.in/automobile...ke-060608.html

Also, I think here in Massachusetts, you have to wait two minutes before it's legal to run a red light. Two minutes feels like an eternity!

[TahoeDirtGirl]

There is another type of traffic signal. Timed. I have alot of timed lights where I am. You can always tell they are timed because at 3 a.m. they always change for a car that just isn't there. I happen to like these because I don't have to figure out where to stand or if it can see me.

[bikerHen]

I've got one fairly isolated light that never changes for me and there is rarely traffic to activate it. I usually just wait for cross traffic to clear and go. Last night I rode home after dark and tried shining my helmet light back and forth across the sensor up by the light. It worked!? But then again, maybe it was because I was on my steel bike instead of my carbon fiber Ruby. The light did a random change for me the other day (while riding my steel bike). In fact I missed my green light cause that's where I usually stop to take a swig of water and blow my nose. Never looked at the light until I noticed the cross traffic stopping. bikerHen

[TrekTheKaty]

YOU GUYS ROCK! Who knew? I JUST SENT AN EMAIL TO MoDOT. Not only do we have a light that doesn't trigger for us, if a car triggers it from the left turn lane--it is the shortest light you've ever seen! We can't get across before it changes.

[Becky]

I emailed DelDOT yesterday about a light that doesn't trip for bikes. This is the response that I received:

"However, in regard to setting traffic signals to detect bicycles, we have not historically set signals to detect bicycles. I’ve been told the problem with doing this, is that most bicycles do not have enough metal for the detection to pickup."

Help me write an educated response, ladies! I wanted to ask the guy if he was advocating bicycles running red lights, but decided that wasn't the most politically-correct way to handle it....

*wanders off to find the 2000 DelDOT Bicycle Policy online*

[Biciclista]

you can direct them to this person:


You stated that your steel frame bicycle does not actuate the signal. It may take some information on how to position your bicycle across the sensor, but it should be able to "see" your bicycle. Even if there was a malfunction and you did not get detected, the eastbound and westbound through-traffic movements are quite heavy, and the vehicles that are waiting behind you will actuate the signal when it is your turn to go.

I have sent a request to our crews to double-check the sensitivity of the detection and verify that bicycles are being detected. If they find that they are not, we will address the problem immediately; it is one of our goals to be bicycle-friendly, and that includes having detection that is sensitive enough to serve the commuting bicyclist. If you need information about how to position your bicycle to ensure good detection, all of the local bicycle clubs have this information and are always happy to share.

I hope that I have addressed all of your concerns. If you have any other questions, feel free to contact me directly at (206) 386-4529 or chris.faulkner@seattle.gov.