Traffic Light Sensors
 

Do those street sensors pick up any signal from our bikes?? I've sat waiting to make a left turn for soooo long last time, is there any way to get those stupid sensors to notice our bikes??? Or is the crosswalk button the only way?? Normally this isnt a problem, but sometimes at night, there aren't many cars to run over the sensors for me.. Also, how good are u all about stopping at stop signs?? Usually I slow to an almost stop, but just roll them a bit.

this is my 3rd week commuting to work/school on my bike, it's working out better then i thought it would :-)

I'll bet you'd have to be pretty heavy so set one of 'em off.

The sensors are actually wires embedded in the roadway with a current running through them; when a sufficently massive ferro-metallic object is in close enough proximity to the wire, it interacts with the electromagnetic field generated by the wire and triggers a change in the light.

You could do the same with a powerful enough electromagnet, or a cast-iron bike. I think the former would be a bit more likely...

Electromagnets powered by yer old Schwinn-Approved generators?

If they are the imbedded wire type where you can see the cuts in the asphalt, stop in the lane so that your wheels are directly on the right side cut (preferably both wheels). If the sensing level has been set right, it should be able to read your presence. On my commute, 95% of the sensors can read me, and the others I just have to work around. If you still don't have any luck with the sensors, call the city road engineer and see what the deal is.

They are called 'induction loops', and are set off depending on the amount of metal in your bike. Weight has nothing to do with it.
The sensitivity can be set higher, so complain to the local authorities if they don't change for you.

I find that some work and some don't. Basically, I've identified the ones that fall into the various categories on my commute. My policy for dealing with the situation is this:

First and foremost, come to a complete stop at the red light. If there is nobody around and the sensor does not work (this often happens and riding at 5.30am is not unusual for me), proceed through. If there are people around, wait. Chances are that someone will come along and set it off anyway. I also use the Crosswalk button sometimes.

Would be considered an attack on society to accidentally leave a medium sized slab of sheet metal at each of those pesky red lights on the route to work?

Call your local DOT shop and register a complaint and/or ask to talk to an engineer. Try to find out when it will be done, and call back after a week if it hasn't been done, or still isn't sensitive enough.

If they can increase the sensitivity, great! Alas, not all sensors are adjustable. We have some old ones around here that cannot have the sensitivity increased. Your only recourse is to press the pedestrian walk button if there is one, wait for a car, or run the light (when it's clear).

I've established a relationship with the local traffic engineer. I'll email him and report unresponsive ground induction loops, and he'll promptly send out a crew to adjust the sensitivity and/or mark the point on the pavement (yellow reflective stripe, about a foot long). I always try to thank him after the adjustment has been made, and it's worked out pretty good.
(The traffic professionals, unlike many SOV motorists, recognize the value of making the infrastructure as bike-friendly as possible. After all, a bike on the road usually means one less car on the road.)

Good. I don't ride on many roads that have heavy traffic, so a quick glance each direction is usually good to go. Use your hearing, too, that helps a lot. And, make sure you work on those bike-handleing skills...I've seen too many people tip over at stop signs because they couldn't roll their bikes slowly and balance at the same time.

velo

As someone mentioned in another thread, the easiest solution to this dastardly problem is to drag a 1956 Chevy bumper behind you.

:rolleyes:

For what it's worth, this is still my favourite solution :D

I've seen fellow riders take their "steel" framed bikes and just step to the side and gently lay the bike down on the pavement as if you were going to leave it there. I helps to see if there are cuts in the pavement as to whether they have the wires embedded in the pavement. If riding with others we always try to get the steel bikes to participate since titanium and aluminum won't work. I first read about this in a bike mag quite a few years ago. I suppose that the strength of the signal would have a lot to do with it too.

sometimes the sensor's "hotspot" is marked - with a cross or X painted in white or cut into the pavement, often in either the upper right or left hand corner. if you don't see those markings but can see the larger outline of the sensor, try placing your crank/bottom bracket at either of the upper corners. in my area placing the crank directly above the hotspot will set most of them off. the cars love it when a solo cyclist changes the light! just kidding.

Wow, junebride, where have you been?

Are you just passing through?

I'm wondering how you'd carry that on your bike?

The areo drag from it alone would be pretty fierce.

Of course, if you had a tail wind, it'd be pretty cool.

What color would you paint that?

Every time the City of Encinitas adds or replaces a traffic signal loop detector, the new one is a CalTrans type D inductive loop, which CAN be sensitized to detect bicycles. Whenever I have trouble activating a traffic signal, I send an email to our city traffic engineer, and get satisfactory results about half the time. We are fighting a much tougher battle to try to get the city and state highway departments to mark the sweet spots of the detectors, perhaps with little bicycle symbols.

I had a chance to work with a gate opening loop and my bike this weekend so I got instant feedback what was working. One of the gates didn't open with the bike, but I layed the bike down over part of the loop and it worked. You can usually see where the loop is cause they cut the road and put them in most of the time. Of course you may look a little silly laying your bike in the road, but it onlyhas to be there a couple seconds to activate it. Or you could just plan on falling at every red light.

Recently, the city has began installing motion sensing traffic sensors. They work really great in the daytime, but when I pull up to them during my pre-dawn commute, they don't turn. I have tried shining my 15W headlight directly at the sensor, but it has no affect. I do not know if these can be adjusted for sensitivity. I guess an email to the city engineer is in order.

That would probably be simplest--plus it would save wear and tear on cleats for clipless riders. :D

You've been watching me, haven't you?

The simple solution for a complex problem!