Nowadays, most parking lots' bars and traffic lights are activated by the detector loops' electromagnetic field being disturbed by a massive chunk of steel passing overhead.
(hat tip to Dai for this concise definition; post #5 @mystery magnet)

Unfortunately, they don't work for me, as my Eco's monocoque is pure plastic and aramide and the steel fork only is not enough ferrous material to disturb the magnetic field sufficiently.
I often do have wait for a long time in front of a red light because my Eco remains undetected and I must avoid parking lots for the same reason.

Is there any way of disturbing the electromagnetic field underneath my Eco which is made mainly of nonferrous body material?
Any electrical engineers here?

Most activation loops have a frequency running, and compares it's  own frequency till it gets disturbed by ferro.
The only good trigger is ferro (metal sheet).
Electrics/electronics can help, if you know the frequency to be disturbed, but too bad, there are lots of different systems with also different frequencies.

Magnets, at least neodymium, you still need a lot, and hope for the best. Not to mention keep your own electronics and paycards away from it

I used to work with a guy called Scott in Portland Oregon twenty years ago who marketed a product known as Green Light Trigger - still available after asking the Google Gods. It was basically a strong magnet encased in plastic. He gave me one which I promptly cable tied to the centre stand brace on my Airhead. Dang it all if that stubborn light on my way home didn't begin to trip when I rolled over the sensor. Scott suggested not rolling directly across the centre of the obvious grooves in the road surface, but to ride as close to the edge of the buried sensor so as to improve your chances of it sensing your bike's mass. I do that out of habit to this day, magnetised or not.

thank you, Arlina and Two Wheels Better, for your answers.

'Electrics/electronics can help, if you know the frequency to be disturbed, but too bad, there are lots of different systems with also different frequencies.'
Arlina, I was not aware of this fact. Too bad for me.

'Scott suggested not rolling directly across the centre of the obvious grooves in the road surface, but to ride as close to the edge of the buried sensor so as to improve your chances of it sensing your bike's mass.'

Two Wheels Better, this is correct.
The density of electromagnetic field lines is higher in the corners of these rectangles

and I always do try to position my Eco directly above one of these lines to enhance the possibility to be detected


But, unfortunately, it only seems to work (or not) at red lights just as soon as there are enough other cars behind me that trigger another loop situated further upstream.*
I was told to try and drive way over the white line telling the cars to STOP HERE but I am too afraid to trigger a red light camera.

*Which unfortunately is never the case at parkings - there is only one loop, very close to the bar. The engine and transmission, situated in the rear end of the Eco, never get close enough to that loop while the front end is already touching the bar. The closed bar.
No way.

To ensure that the light will always be triggered you should tow it behind a car.

(Sorry. Couldn't help myself. )

thanks anyway, duck
you made my day

version 2.0: to tie a car underneath my Eco. last time I tried that approach, it worked perfectly.
The problems started when I entered the parking: the car and the Eco on top of it were higher than the ceiling. minus one Eco. duh. never again

BTT

If it's a magnetic field that triggers the light I wonder if an electromagnet mounted low on the bike would work. 

It's been about 50 years since I studied electromagnetism, but I think a couple hundred turns of magnet wire around an iron core with a push button to power it up when needed might do the job.  You could get a pretty high flux density in a relatively light weight package.  The shape of the core could help direct the field to where it is needed.

Think how much magnetic force is generated in the starter motor.

I have this issue going home late at night at some traffic signals.

Its a case of wait for something bigger or go throughh the red. Correspondence to the powers that be complaining about the issue is in place in case a discerning policeman decides to 'investigate'.

Point-Seven-five wrote:If it's a magnetic field that triggers the light I wonder if an electromagnet mounted low on the bike would work. 

It's been about 50 years since I studied electromagnetism, but I think a couple hundred turns of magnet wire around an iron core with a push button to power it up when needed might do the job.  You could get a pretty high flux density in a relatively light weight package.  The shape of the core could help direct the field to where it is needed.

thank you so much, Point-Seven-Five

These were my thoughts, that's about what I do remember from school. Some forty years ago...

The question now is how to find out.