Biker stuck at lights… as he is too light!

**Bob** · 27th July 2007, 00:19

Bikers in Sacramento found they were being delayed at the lights… and delayed… and delayed… until someone else came along and triggered them.

The reason? Local authorities had installed pressure-sensitive sensors to trigger the change of lights… but hadn’t taken into account the light weight of a motorcycle.

Embarrassed local officials have installed a ‘more sensitive controller’, allowing for increased capability of detecting metal. Rick Dondro, assistant director of the county Public Works Department said the old controller couldn't detect motorcycles because they contain less metal than cars. They have now asked local bikers to bring their bikes to the intersection to help them set the new controller to recognise bikes.

**xwhatsit** · 27th July 2007, 00:35

Hehehe yeah been-there-done-that, haven't we all here in NZ?

I've just found a new one that doesn't even respond to my side-stand trick; the end of Epsom Ave, at the intersection with Gilles Ave. It's great fun holding a steady 55kph through the chicanes, but then you have to wait for the cages crawling along at 20kph to catch up with you and trigger the lights.

**sAsLEX** · 27th July 2007, 03:38

Originally Posted by Bob

Local authorities had installed pressure-sensitive sensors

Embarrassed local officials have installed a ‘more sensitive controller’, allowing for increased capability of detecting metal. Rick Dondro, assistant director of the county Public Works Department said the old controller couldn't detect motorcycles because they contain less metal than cars.

So do they measure weight or magnetic inductance?

**Bob** · 27th July 2007, 08:50

Just been back and looked at my source information.

Doesn't make it clear, but it does initially refer to that fact that a "bike doesn't weigh enough to trigger the sensors that will turn the light green" - but then goes on to say "Rick Dondro, assistant director of the county Public Works Department, said a more sensitive controller recently was installed at the intersection, allowing for increased capability of detecting metal. He said the old controller couldn't detect motorcycles because they contain less metal than cars."

So - maybe - they had a weight-sensitive sensor, but then replaced that with a sensor that picks up on metal... but again blew it as it was calibrated to react to a much larger metal area/volume of metal?

Whatever happened, at least they're trying to get it right!

**Morcs** · 27th July 2007, 09:12

Theres a set of lights by repco massey at westgate that never changes late at night... I end up sitting there for ages, then jumping the red...

Really pisses you off if you are one of those people who keeps in gear with clutch in at the lights, you wont put it into neutral as they will change 'any second'... your clutch hand soon diiiieeeeees...

**BMW** · 30th July 2007, 18:17

Originally Posted by Bob

Just been back and looked at my source information.
Doesn't make it clear, but it does initially refer to that fact that a "bike doesn't weigh enough to trigger the sensors that will turn the light green" - but then goes on to say "Rick Dondro, assistant director of the county Public Works Department, said a more sensitive controller recently was installed at the intersection, allowing for increased capability of detecting metal. He said the old controller couldn't detect motorcycles because they contain less metal than cars."

So - maybe - they had a weight-sensitive sensor, but then replaced that with a sensor that picks up on metal... but again blew it as it was calibrated to react to a much larger metal area/volume of metal?
Whatever happened, at least they're trying to get it right!

Most new lights use a sensor on top of the light ( you can see the 'yellow cone") and these do not pick up 'weight' or the magnetic parts of the bike.

Instead they project a 'cone' out from the light that looks for disturbances.

To trigger the light (try this at Westgate as last time it worked for me!) kill the engine and restart it.

This electromagnetic disturbance causes the cone to think there is something really big there! And makes the light have priority!

There is someplace a time frame you have to wait before running a red light.

Hope this helps!

**sAsLEX** · 30th July 2007, 23:59

Originally Posted by BMW

Most new lights use a sensor on top of the light ( you can see the 'yellow cone") and these do not pick up 'weight' or the magnetic parts of the bike.

Instead they project a 'cone' out from the light that looks for disturbances.

To trigger the light (try this at Westgate as last time it worked for me!) kill the engine and restart it.

This electromagnetic disturbance causes the cone to think there is something really big there! And makes the light have priority!

You contradict yourself there.

If it were a passive IR then doing that would have no effect..... unless it were the traditional inductive loop.

**SARGE** · 31st July 2007, 00:03

i dont run the lights .. just feels wrong somehow .. but i have no problem riding up on the footpath and turning left .

**nadroj** · 31st July 2007, 07:02

Just sit there & pay back all those cage drivers who's colleague fucked up. 5 minutes is enough to get the point across & one of them will report it on your behalf.

**xwhatsit** · 3rd August 2007, 12:39

Originally Posted by SARGE

i dont run the lights .. just feels wrong somehow .. but i have no problem riding up on the footpath and turning left .

Hahah yes, I've been known to do the same thing on occasion

There's definitely something hard-wired into my brain that red light = bad. It takes a serious amount of frustration with just sitting there at night in the freezing cold before I am able to just go through the light -- even though I'd normally go through that intersection (with no lights, just a Stop sign) in a flash.

**Tim 39** · 3rd August 2007, 13:42

most in Dunedin have the pressure sensors, there are 4 squares on the road, if you park the whole bike on one of the squares it's enough to trigger them

**Sidewinder** · 5th August 2007, 05:34

thats why you do stoppies at lights like our mate jade does. it put all the weight on the front and it will trigger it off!!!!!!!!!! click click make it click!!!!!!!

**lordandrevv** · 7th August 2007, 10:35

from what i have heard there are some kind of sensors in the ground that detect metal. While mass has no effect on the sensor, the amount of metal above it does. If you have a look at big intersection on the bicycle lane, sometimes there are 3 triangles painted on the road. They represent a sensor that is sensitive enough to pick up a bicycle. That's what I've heard is used in CHC....

**cooneyr** · 8th August 2007, 07:58

Originally Posted by sAsLEX

So do they measure weight or magnetic inductance?

Magnetic inductance in NZ

Originally Posted by BMW

Most new lights use a sensor on top of the light ( you can see the 'yellow cone") and these do not pick up 'weight' or the magnetic parts of the bike.

Instead they project a 'cone' out from the light that looks for disturbances.

To trigger the light (try this at Westgate as last time it worked for me!) kill the engine and restart it.

This electromagnetic disturbance causes the cone to think there is something really big there! And makes the light have priority!

There is someplace a time frame you have to wait before running a red light.

Hope this helps!

Wrong those cones have nothing to do with detecting vehicles we use magnetic inductance loops

Originally Posted by Tim 39

most in Dunedin have the pressure sensors, there are 4 squares on the road, if you park the whole bike on one of the squares it's enough to trigger them

Again wrong.

Originally Posted by lordandrevv

from what i have heard there are some kind of sensors in the ground that detect metal. While mass has no effect on the sensor, the amount of metal above it does. If you have a look at big intersection on the bicycle lane, sometimes there are 3 triangles painted on the road. They represent a sensor that is sensitive enough to pick up a bicycle. That's what I've heard is used in CHC....

The 3 diamonds just show you where to stop on a treadly. All loops should be capable of picking up a treadly or motorbike if you know where to stop. Sometimes however the loops get broken and dont work as well as they should.

All loops are actually a single loop of wire wound around the two squares in a figure 8 fashion. I'm not a electrical engineer but a civil eng so here is my interpretation - There is a small current flow through the loops that causes a magnetic field to be generated (physics 101) when the field is disturbed by the presence of a metallic object then the sensor senses.

If you stop on the sides of the squares that are touching i.e. middle line of the "loops" you should trigger the sensors. This is generally the center of the lane which treadlies very realy go near hence don't trigger the sensor. Bikes tend not to stop there either but if you do

See attached pic of where to stop.

Cheers R

**davereid** · 8th August 2007, 20:29

The lights are supposed to change for a vehicle.

If they don't change they are faulty and you have the right to ignore the lights and use the right-hand rule. You don't have to do dodgy side stand actions or hop off and press the pedestrian cross button !