No. After a resurfacing, the cuts are buried. But over the saw cuts, the pavement is supported well so cracks develop. They are big cracks but if you see linear cracks of roughly a car's length, that the old saw cut.

Look at picture that DanoXYZ posted. Your wheel will do a much better job than plates, magnets, bolts, cleats, etc. There's no need to kludge together something when you have wheels that will do the same job.

unless you have a carbon bike AND carbon wheels. But then why would you ride such a thing on public roads in traffic?

With regards to carbon rims that may not trigger the sensor.

I know that metal rims will work better than shoe inserts.

Carbon rims probably aren't going to be used too much in commuting, at least not yet. However, carbon fiber is conductive. I've had carbon fiber fly rods snap in my hand just before thunderstorms hit. I'd certainly try the same trick if I ever decided to buy carbon wheels...which isn't anytime soon.

oh yeah I keep forgetting that CF is conductive.

around here they seem to always put down new sensors when they repave. Not sure what is up with that, but at all the intersections where I want to trigger the light, it's clear there are saw cuts. There is only one road on my commute that seems to have sensors but doesn't have cuts, and the road is brand new. There is a crack that I think may mark the sensor, but cars keep coming along and ruining my experiments in triggering the light

If they are just putting new asphalt down on top of old, rarely are new loops put down here. If they rotomill the asphalt, they may break the old wires and have to replace them. That's dependent on the depth of the milling.

Yes! A magnetic field will only induce a current (and resultant back-EMF) when a conductor moves through it. The higher the velocity the higher the induced-voltage. It's like those hand-cranked emergency flashlights; the faster you crank the handle, the more power you generate and the brighter the light. If you creep up to the light very, very slowly, you may never trigger it.

I'll need to look up the amount of induced current in various types of conductors. I suspect CF may not be as good as aluminium, which may not be as good as steel, and copper may be the best. I've found with motorcycles, if you hit the starter button, the EMF from the starter motor is enough to trigger many of these sensors.

that's probably it, haven't seen them put down a new layer without pulling up the old in recent memory.

Happens here all the time. Sometimes they just mill the edges so that the new asphalt will be flush with the concrete curb/gutter along the sides, but the middle portion just goes over whatever was there. Obviously not ideal, but I guess it saves some money.

About a year ago, I'm sitting at a light I stop at every day, and a guy stops behind me on a motorcycle, way way behind me. I wave him up and tell him "I need more metal on the loops to make this light flip, they don't have it adjusted right". Turns out he's a local cop, off duty, and he says he'd mention it to the right folks.

3 days later, light changes whenever I'm on it.

They can adjust these things, they just don't think to do it.

That figures. As soon as the light stops counting down, it doesn't change for me. I think it figures I was a car that turned right. Several around town seem to have been reprogrammed that way.

fify

OK that was a bit of a joke... but the bottom line is that few motorists really study traffic and sensors or even the law the way that some of us cyclists do.

I often study the traffic patterns of different routes to see what works out best, and what is safest. Later I may share the results of my study with my wife by telling her to go such an such a way to avoid lights or other inconvenient situations when she is driving. She will look at me as if I am crazy, but eventually tries the suggested route only to find that hey.... her engineer hubby might be on to something.

But most motorists... they just rely on the application of "more power" as a solution.

You'd be better off putting the magnets on the bottom of your shoe and then unclipping... sorry.

There is also a new type of sensor... I watched the whole evolution take place on one of my neighborhood streets. This is a camera sensor and it apparently looks for some object that appears in the field of view and has a certain contrast before it changes.

On this particular street, I could never get the loop to trigger... and later the engineers told me that the loop was bad and could not be adjusted, so they replaced it with a video sensor.

Now I find that if I approach right in the center of the lane, the light triggers just moments after I get to the stop line. If I arrive in the dark and don't have lights... no trigger. If I wear dark clothing, no trigger. But with that in mind, I know how to trigger the thing and now dress and light accordingly.

The video sensor is the trickiest one to trip. I can trip them at night because I can either shine my helmet light on them or the notice my lights. During the daylight, the cameras are specifically calibrated to ignore narrow targets like pedestrians. Often cyclists fall into this category. I've found that if I stand at the light waving my arms like an idiot I can trip the light about 50% of the time.

Of course, if the light doesn't trip, I treat it as a malfunctioning light and proceed...with caution.

I'm pretty sure Colorado law says a cyclist can proceed through a red light after stopping, if it is safe and clear to do so. I know Idaho, Tennessee, and Mississippi have laws specifically stating so. Likewise a Stop sign can be treated as a Yield sign if it is safe and clear to proceed.

Of course that doesn't help you if you're trying to go straight across or turn left onto a busy road, with no other cars on your side of the intersection.

Incorrect.

Okay CO apparently does not allow it, but some states do.

Idaho Stop actually means 2 things:

1) Stop sign: that a bike can do a rolling stop if there is no traffic (treating a stop sign more like a yield sign)
2) Red Light: that a bike can can stop, then can immediately proceed (treating a red light like a stop sign).

Then again, if you don't live in Idaho, it doesn't make much difference what it says. ;-)


I would like the text of the statute that says you can proceed through a red light after a predetermined time. I've never seen a statute that says that. would make sense though.

Don't you guys just press the little "I want to use the crosswalk" button? :-O

Wow, I find my local video sensor works great.

Here in San Diego, we have an on line form that we can use to send complaints to the street division... and if I were having issues with that sensor, I would send them a complaint... but it works better than any other sensor I can think of...

Now as far as that complaint form, I do use it often.... and complain about things from bushes into the bike lane to bad pavement to non working sensors... and they send back responses and task numbers. And I follow up.

Do you have such a complaint form locally?

Only Idaho.

Most other states have some provision for acting as if the light is broken and allowing you to proceed after some wait period... which could be time or watching the light otherwise cycle.

Not all locations have such a button... and accessing such a button can be a real pain if you are turning left, AND are already in the lane, waiting. Otherwise you just have to act like a ped. Some locations force peds to cross in areas on the other side of the street... on the south side for instance where a sidewalk may exist, while you are on the north side heading west on the street... so no button.

well crap, I could have sworn I read about going through a red light in the MS state code, but now I can't find anything about it.