Actually I face both the problem of both paved over and too many changes. One area near my home in the northern direction has been paved over and I can't figure out where the loops are.

In the eastward direction there are old loops visible with new loops... and I can't tell which are old and which are new.

I have reported both to the city... with no change.

Results after 3 days of trying to trip the signals:

Intersection #1... 3 for 3 success
Intersection #2... 2 for 2 success... 3rd time I had a car trip it for me.
Intersection #3... 0 for 1.5 success... 1 time a car tripped it for me. The other I couldn't tell if it was me or the car that came up behind me. It definitely wouldn't go the first time. I don't use that intersection much and only went that way on purpose to try it out.

In any event, thanks for the education. I never even tried because I had always read or heard that bikes wouldn't work.

Now you can impress the natives with the magic flame;)

Depending on the city and the lights and time, I've found that many lights that operate on sensors still have a timing function to change just in case they didn't get 'tripped' properly.

The city I ride in has all of the lights in downtown on timers to facilitate traffic flow. Especially one road. When I'm driving if I can made the first light I can make the next 8 lights (all the way through downtown) just by driving the speed limit.

Here's an interesting (to me at least) anecdote. The left turn signal to turn into my neighborhood pretty much never triggers for me while I'm on my bike. I reported the signal to the state and they told me that no signals in the state are set up to detect bikes. They never responded when I mentioned that I don't have this problem anywhere else but at this particular light. It's not a big deal as left turns are free but at high traffic times, that can sometimes mean waiting a few minutes.

So a few weeks ago, I had the studded tires on my commuter due to some snow and I pulled up at the light in the same spot I always do (right in the center of the lane over the wire) and lo and behold, I get the left turn signal. The next day, I watched a motorist stopped at the light and he did NOT get the left turn signal when the light went green. This either lends some credence to the possibility that some sensors are so sensitive that a small change in distance from metal to the wire could have an effect (my studs are closer to the ground than the metal rim of a car wheel), or the signal is just intermittent.

Either way, these types of threads are why this forum is so useful.

Absolutely. When I had both a 600 pound motorcycle and 23 pound bicycle one local detector would pick up the bicycle just fine, but not the motorcycle. I positioned both exactly the same- over the sawcut. The bicycle has 1" tires while the motorcycle tires had 4" tall section cross sections.

On my daily commute I have a left turn with an arrow that USED to change regardless of whether a vehicle was waiting. Then one day a year ago the DOT changed it to only signal when triggered.

I'm not a scofflaw at all so I contacted our local liaison to the NCDOT and asked them to change it back. She forwarded their response, which was (essentially), "We'll consider it. In the meantime try making sure your bicycle is right in the center of the lane [I'd already been doing that to no avail]. If that doesn't work just run the light when it's safe to do so."

I've always wondered whether a police officer would buy that justification if I made the left without a signal (now it changes some times but not others; this morning it didn't). "But officer, the DOT won't fix that light and they even TOLD me to run it!"

And yes, I did keep the email. ;)