Interesting moment at a busy intersection yesterday

[sparky_1]

I had an interesting experience yesterday while aimlessly driving in western NH.

I turned left out of a rural downtown and came to a four-way intersection to turn onto a major state road. That state road had two lanes travelling in both directions. My roadway and the one across from me had the typical left turning lane and a lane for going straight ahead or yield/merge right.

I was in the left turn lane to head east on the major state road. I was car number two. The lane to my right had about 4 cars stopped when I pulled up.

I see the major road stop for their red light, then see the people across from us make their green light moves. I figure in a bit we’ll get our green light.

Wait

Wait

Then the major road starts moving again.

Hmmm. Weird, but it happens.

By this time cars are filling up behind me and to my right.

Cycle changes again and the people across from us make their turns.

Then the major road begins moving.

WTF?! Repeat above again for another few cycles. Did the light break?

I can see people behind me getting mad. I’m getting mad. I, and everyone else have nowhere to turn as a three point turn would never work in the tight intersection.

Finally, the car in front of me pulls forward about 10 feet. Then I see it: the car in front of me and the head car to the right were both stopped a car length from the white line. I should have noticed since the car to my right (number two) was able to pull into the right merge lane because the front car was back too far.

Realizing this, I honk and lower my window and tell the car at the head of the lane to my right that I think they’re too far back to trigger the light. They give a bewildered look and pull forward all the way. This causes the person in front of me to farther pull forward to match them.

Within 20 seconds our light turned green and we were all off.

It was really pretty crazy to sit their the whole time and have no idea what to do/no where to go. And it wasn’t the length of time, but knowing that the situation was not going to change. Does someone get out and act like a traffic guard at a busy intersection so that our intersection can be unclogged/turned around?

It was also weird that neither car in front realized how far back they were.

I wonder if it’s just because I ride a motorcycle and so would know about how the lights are triggered (my bike is too light to reliably set off the lights - frustrating).

Again, just an interesting moment.

[John_DiFool]

People seem surprisingly ignorant of those underground sensors.

[Joey_P]

There’s an intersection by my house where the double left turn lane (it’s own lane, with concrete boulevards on both sides of you) has the white line set about a car length back from the end of the boulevards. I believe it is setup like this to make it so that the cars coming from you’re right, making a left turn don’t have as hard of a time getting around you. If you pull up to what feels like it should be the right place to stop at a red light you’ll be exactly one car length past the trigger. This happens a lot more often in winter when you can’t see the lines to begin with. I’ve actually emailed the city about it a few times. What makes this dangerous is that if your past the line there’s still a green light, but you have to sit there like an ass with a red arrow. After a cycle or two people just run the red arrow.

Now, when I’m in my car, I really don’t care as I just make sure I’m on the sensor when I get there. The problem is when I’m on my bike. See, my bike can’t trip the this sensor so I have to rely on other cars to do it for me. Further, as a motorcyclist in Wisconsin, under certain conditions I can run a red light. The problem with that is, when I go through it after sitting there with the person who pulled ahead to far for 2 cycles, they’ll usually run it with me.

The only time this is nice thing is if I’m on my bike and someone pulls up behind me, I’ll pull up past the white line and this get’s a car onto the sensor.

Here’s the intersection. If you look at the red car and the white truck you can see why so many people pull past the white line. The boulevard extends about a car length past the line, and the boulevard ends about a car length before the cross traffic starts, so when you stop at the white line you feel pretty far back and you can comfortably pull up.
ETA, the letter I sent to the city suggested that they change the way the sensor is setup so that instead of a car having to be on it to trip it, it would give the green arrow if someone drove over it during the time there wasn’t an arrow. IME, they are usually setup that way in left turn lanes that you can’t get out of like this one. My other suggestion that I thought they might actually take was to just put a sign at the white line that said something like “STOP HERE ON RED” or “Stop at white line to trigger green arrow” or something along those lines. Maybe I’m better off just getting another magnet for my bike. I’ve got one and it works on some intersections but it’s still doesn’t work on this one.

[pudytat72]

@sparky_1

I wonder if it’s just because I ride a motorcycle and so would know about how the lights are triggered (my bike is too light to reliably set off the lights - frustrating).

I googled “underpavement car sensors” and found this information:

“An inductive loop is simply a coil of wire embedded in the road’s surface. To install the loop, they lay the asphalt and then come back and cut a groove in the asphalt with a saw. The wire is placed in the groove and sealed with a rubbery compound. You can often see these big rectangular loops cut in the pavement because the compound is obvious.”

Since the wire is in the groove, maybe if you rode you motorcycle directly over the groove, or very close to the groove, you might be better able to have enough pressure to trigger the light.

(I thought about suggesting that you get inside the rectangle and stand up on your bike pedals and sit down REALLY HARD. You might add enough force to trigger the light. But that might get you some WTF looks from the other people at the light. )

[Joey_P]

@pudytat72

I googled “underpavement car sensors” and found this information:

“An inductive loop is simply a coil of wire embedded in the road’s surface. To install the loop, they lay the asphalt and then come back and cut a groove in the asphalt with a saw. The wire is placed in the groove and sealed with a rubbery compound. You can often see these big rectangular loops cut in the pavement because the compound is obvious.”

Since the wire is in the groove, maybe if you rode you motorcycle directly over the groove, or very close to the groove, you might be better able to have enough pressure to trigger the light.

(I thought about suggesting that you get inside the rectangle and stand up on your bike pedals and sit down REALLY HARD. You might add enough force to trigger the light. But that might get you some WTF looks from the other people at the light. )

On some lights if you just keep the bike over the loop you’ll be okay. They used to suggest putting your kickstand down, but that can cause other problems (for starters a lot (all?) bikes have safety switch that will kill the engine if it’s in gear and you put the kickstand down). You can get a magnet to mount on your chassis to help change the light. But as I said upthread. They don’t work on all lights.

[sparky_1]

@pudytat72

I googled “underpavement car sensors” and found this information:

“An inductive loop is simply a coil of wire embedded in the road’s surface. To install the loop, they lay the asphalt and then come back and cut a groove in the asphalt with a saw. The wire is placed in the groove and sealed with a rubbery compound. You can often see these big rectangular loops cut in the pavement because the compound is obvious.”

Since the wire is in the groove, maybe if you rode you motorcycle directly over the groove, or very close to the groove, you might be better able to have enough pressure to trigger the light.

(I thought about suggesting that you get inside the rectangle and stand up on your bike pedals and sit down REALLY HARD. You might add enough force to trigger the light. But that might get you some WTF looks from the other people at the light. )

Sadly, just riding on the groove does not work. I have best success if I weave back and forth across my lane as I approach the stop in order to hit multiple grooves. Though this seems to work, it makes me look a bit… drunk? Not a good thing.

[elfkin477]

@sparky_1

I wonder if it’s just because I ride a motorcycle and so would know about how the lights are triggered (my bike is too light to reliably set off the lights - frustrating).

Nope, you just encountered some idiots. It’s hard not to know the sensors exist - you can often see them a bit after months of snow plowing.

[Vlad_Igor]

@Joey_P

… The problem is when I’m on my bike. See, my bike can’t trip the this sensor so I have to rely on other cars to do it for me. Further, as a motorcyclist in Wisconsin, under certain conditions I can run a red light. The problem with that is, when I go through it after sitting there with the person who pulled ahead to far for 2 cycles, they’ll usually run it with me.

I had the same problem riding my bicycle around a college town many years ago. I knew the trip wires were induction coils, so I cut an 18" length of a broom handle and nailed a donut magnet on the end of it. If I were the first (and often only) vehicle in the left turn lane, I’d unclip the broomstick, wave the magnet over the trip wire, and the left turn signal would light up on the next cycle.

[Kiwi_Fruit]

I’ve read that using your electric starter on a motorbike can trigger the inductive sensors. Mostly I ride so that I go over as much of the loop as I can by being to either side of centre.

BTW, pudytat72, the sensors are electrical induction, not pressure, so weight doesn’t trigger them. The wikipedia article has a small section about them.

[Sunspace]

In Toronto they put three large dots on the part of the induction loop that you’re supposed to stop your bike over. But I also believe the sensor has to be adjusted somehow to pick up the lesser metal mass of a motorcycle or bicycle.

[Serenata67]

@Vlad_Igor

I had the same problem riding my bicycle around a college town many years ago. I knew the trip wires were induction coils, so I cut an 18" length of a broom handle and nailed a donut magnet on the end of it. If I were the first (and often only) vehicle in the left turn lane, I’d unclip the broomstick, wave the magnet over the trip wire, and the left turn signal would light up on the next cycle.

Now that is a smart answer to the problem! You should sell those… I’m sure there are bikers who would buy them!

[Bookkeeper]

@Sunspace

In Toronto they put three large dots on the part of the induction loop that you’re supposed to stop your bike over. But I also believe the sensor has to be adjusted somehow to pick up the lesser metal mass of a motorcycle or bicycle.

Same here. Maybe it’s a provincial standard?