Triggering traffic lights with a magnet - does it work?

[Steam]

[B]... if the blurb is correct, it would seem that any strong magnet would work, such as from a speaker.

From what the physics guy said in a quote on page one, magnets don't work.
They have no effect on the sensor, and he gave reasons:

{A Magnet} Will not work, at least not better than any non-magnetic metal lump.

Traffic light sensors are inductive loops in the road surface (sometimes you can see the cuts in the asphalt where it is). An alternating current is sent through the loops, and if metal passes over it, the magnetic field from the loop causes eddy currents in the metal, which will alter the electrical characteristics of the loop. These altered characteristics can be detected. It makes no difference if the metal a magnet or not, just that it is an electrical conductor. In a way, it's just a big metal detector. So a magnet will make no difference.

or are they made of an alloy which would not be magnetic and therefore would not affect the road induction wires?

Yeah, my wheels are alloy. I think most are.