Stop Light Changes (did a search, and called my local department)

[GregWantsYZFun]

up in Humboldt...we do things differently

For what it's worth, being a Deputy here in Humboldt, and a rider, if someone politely explained the problem, and didn't cause a wreck, my conversation would be more about what they were riding :ride
GOJO

 

[kstotz]

Here's the types I know about:


Damped
Oscillator- The loop is part of an oscillator circuit. The oscillator is held just on the verge of oscillation via AGC. When a car enters the loop it "dampens" the loop by absorbing energy, and the oscillation decreases or stops entirely. The circuit needs a very long time constant in the AGC loop in order to detect slowly moving vehicles, because whatever time constant you start out with is reduced by a factor equal to the effective loop gain of the AGC.

Eagle Signals had a product of this type in the '60's. It used a partially charged NiCd battery as a huge capacitor to get the long time constant required.

The main disadvantage is that every loop will have a slightly different natural frequency of oscillation, and the interactions between adjacent loops are nasty due to beat frequencies (imagine a straight-through lane right next to a slip (green arrow) lane).


Fixed Drive- A fixed frequency oscillator and driver drives the loop from a high drive source impedance. When a car enters the loop, the loop voltage drops by a very small percentage. The drop is detected. The circuit requires a differentiator/amplifier which can pick up loop voltage changes as low as .5% of the total, with a time constant of several seconds.



Ringing Coil (I am only guessing on this one, from the odd thing I've heard). A microprocessor "pings" the loop with a short pulse then evaluates the amount of ringing. This will vary depending on the damping in the loop.

This would have the advantage of not being restricted by the comparatively short time constants you must live with in analog designs, so the detection of slow moving and even stationary vehicles would be easier.

I've had pretty good results by simply rolling backwards and forwards(additive fielding) a few times, but, depending on the type of sensor, this might not always work....

 

[mayorofnow]

This thread has inspired me to look up the traffic engineer for SF and report a turn signal I haven't been able to trigger. Thank you!

 

[DonTom]

He also stated that it was my responsibility to find the sensor. Under no circumstances was I to proceed carefully through the red light. He stated that all of his officers would cite me if I did.

I would like to see the outcome to that in traffic court.

What are you supposed to do, stay there all day with cars behind you and then get a ticket for impeding traffic?

I call BS to it being your responsibility to know where the sensors are. If there is a sign that says "motorcycles stop exactly on this spot" then they could have a point.

I have the same problem at a couple of spots. One here in Auburn and another in Reno. When safe, I go on red. It's to the point that I no longer wait because it NEVER detects me. But if there is a car in front of me, no problem, and then I will wait.

BTW, "When safe, I go on red." means when there are no cars or cops around.

BTW, I hope that cop gets behind you on red when the light doesn't change. Just stay there all day and see what happens. I bet the cop won't even know where you should stay for the sensor to detect you. Besides that, it probably won't even if you're right on it. Depends a lot on the bike, ground clearance and such.

I have also seen the camera type sensors NOT detect ANYTHING. All it takes is for the sun to be shining into them. I had that issue at the same time, every day, when I lived in South San Francisco on my way back from work. And that was in a car! But of course, I could wait there until it got dark every day. But I had better things to do with my time after work.

BTW, I know NV has a law that you have to wait two cycles (IIRC) when you're not detected. Doesn't CA have such a law?

-Don- Auburn, CA

 

[gixxerjeff]

I would like to see the outcome to that in traffic court.

:laughing
You've had plenty of time.
You are responding to a 13 year old post.

 

[DonTom]

:laughing
You've had plenty of time.
You are responding to a 13 year old post.

Very easy to do when the last poster was just yesterday and then I check the parent message.

I see the guy I responded to has not been in this forum for ten years. That's enough time for a few laws to change.

So what is the CA law on this? I assume after two cycles you can blow a red light when safe, just as in NV.

But "when safe" probably means no cops around.:laughing

-Don- Auburn, CA

 

[ScottRNelson]

So what is the CA law on this? I assume after two cycles you can blow a red light when safe, just as in NV.

There is a law about a malfunctioning traffic signal that I would have claimed if ever caught for going through a red light that wouldn't change. I always made sure that I had waited at least 30 seconds before going because sometimes they do change. The "cycles" thing doesn't always work. There is a signal at the corner of Bernal and Foothill in Pleasanton, a T-intersection, that won't go through any cycles if there isn't a car in the right direction. You could probably sit there for an hour at night headed northbound with no changes.

Here in Idaho, there is a recent law on the books that lets motorcycles go through lights that won't change for us. I can't remember the exact details, but it's mentioned in the Idaho Motorcycle Operator's Manual. There's another cool law here that lets you exceed the speed limit by 10 mph when passing somebody too.

 

[CDONA]

Did you ever roll up behind one car ahead, at a light, and wait?
The car was creeping forward the whole time until out of position.
I went thru two light cycles, don't know how long that car was stuck.
I back up and signal the driver ahead to reverse back to the limit line, that he was way over.
We have to help cagers out, to be as smart as :ride

PS I got stuck twice in one intersection in Fairfield yesterday.
Working on a left turn, no signal trip.
Moved over to the right, to go straight thru same intersection, waited for another cycle, then ran the light

 

[ScottRNelson]

Did you ever roll up behind one car ahead, at a light, and wait?
The car was creeping forward the whole time until out of position.
I went thru two light cycles, don't know how long that car was stuck.
I back up and signal the driver ahead to reverse back to the limit line, that he was way over.

I was leading a group ride out of Folsom once with about eight bikes. At the intersection of Grant Line Rd and Jackson Rd (Highway 16), we couldn't trip the sensor. Eight bikes and it didn't detect us. We finally all squeezed up near the front and motioned a semi that was following us to pull up and trip it for us. That worked. That's another intersection where you could be stuck forever if the light doesn't change, except that during the day there is enough cross traffic that you might not be able to safely cross against a red light.

 

[bojangle]

CVC 21800(d)(1) The driver of any vehicle approaching an intersection which has official traffic control signals that are inoperative shall stop at the intersection, and may proceed with caution when it is safe to do so.

I will, if possible, wait one full cycle. When the light doesn't change when it should have, I proceed when clear and safe to do so. Motorcycles are registered vehicles and pay state registration fees. Therefore, it is the responsibility of the authority maintaining a signal light to ensure that it operates correctly for all registered vehicles. At least that would be my argument in court. When it is clear that the signal is malfunctioning because it won't detect your motorcycle, CVC 21800(d)(1) should cover that. Just make sure you wait long enough to where the signal should have functioned for you.