Every scooterist has faced this at one time or another, those damned traffic light sensors that your scooter can't trigger.
I've seen discussion of this on several scooter forums, but really never expected to see it addressed in the mainstream media. But apparently, the Columbus Dispatch has tackled a story that other papers have been afraid to touch... perhaps out of fear of losing the advertising dollars of those traffic-light-triggering magnet vendors. ( I kid, of course, I kid.)
The long and the short of it is, those sensors detect metal, not magnets. You are best off positioning your scoot on a corner of the rectangle. You will have better luck with a classic metal-body scoot than one with plastic panels. And finally if nothing else works, and you want to modify your scooter to trigger the sensors, mounting a metal plate with as large a surface area as possible will be more effective than some snake-oil magnet.