Many of the sensors in Beaverton are actually tied to a camera. I've found that to trip those on wet nights is to locate the camera, and shine my helmet light directly at it.
They work when they detect a large change in the values of the pixels in the sensitive areas.
So, if you don't see a diamond, or circular cut, and you know that the intersection is not set by a timer only, look for those cameras.
Riding my bike is MY pursuit of Happiness!!!