Demand activated Traffic Lights

[Alembicbassman]

Contrary to what I thought it's not the weight of the vehicle running over the sensor that activates the green light, but the disturbance in the magnetic field of the inductance loop burried in the road.

So if you want a better chance of initiating the green light you need a higher concentration of ferrous metals.

Answer: Ditch the carbon and buy steel.

 

[jimboalee]

If the lights turn red against you and there is no traffic in the transverse directions, you get off your bike and become a pedestrian pushing a bicycle. Walk it to the far side, get back on and continue your journey.

 

[Tynan]

really? I'd have thought detecting something heading towards it at x mph would be trigger enough

 

[gaz]

[QUOTE 1193610"]
Correct, and this is what is included in the make up of speed cameras. Hence why it is almost impossible to set one off if you have no ferrous metals on your bike.
[/quote]

no all speed cameras opperate in that way, you get some which are scanning all the time. although this is becoming rare.

really? I'd have thought detecting something heading towards it at x mph would be trigger enough

But your heading away from the speed camera (unless it is one facing towards you which isn't common)

 

[Norm]

[QUOTE 1193613"]
No they don't.

They have two sensors in the road. One for weight and the other which is magnetic.
[/quote]
Truvelo and Peek cameras work on loops in the road but Gatsos use radar and SPECS measure average speed using the time to travel a measured distance.

 

[HJ]

Contrary to what I thought it's not the weight of the vehicle running over the sensor that activates the green light, but the disturbance in the magnetic field of the inductance loop burried in the road.

So if you want a better chance of initiating the green light you need a higher concentration of ferrous metals.

Answer: Ditch the carbon and buy steel.

Yes, there was an amusing incident on the Edinburgh - St Andrews cycle ride a couple of years age, a couple of hundred riders set off on mass from a park in Edinburgh. As they reached the first traffic light it turn red, so they sat and waited, but as there were no steel framed bikes over the inductance loop, just £100K + of carbon fibre, aluminium and Titanium, the lights didn't change. We were there for about 15 minutes before the police turned up and stopped the traffic to let us through the red light. They then had to provide us with a rolling escort to get us out of town....

 

[Alembicbassman]

Got some neodynium magnets at work that we use to release the security tagged items. Going to put one on the bottom bracket to see if it works.

These magnets are really powerful.

 

[DrSquirrel]

drop them on the road and see how it copes...

 

[Chutzpah]

Cyclecraft recommends trying to cycle diagonally across them.

As far as I know they're magnetically triggered only. Not sure how they're meant to detect weight.... the sensors are buried in concrete...