Radar detector false alerts

i have the passport 8500...great detector.
the only mystery i have is that it goes off in the same spot
everyday. its an intersection with a traffic light in a medium
populated suburb. no electric signs, no businesses, just the
electical box for the light.

the passport does pick up residuals from radar guns where
cops usually hang out, but i haven't seen one in years there.
its a very strong signal too.

any ideas?

 

Is it on X band? Is it possible that there's a photo radar at that traffic
light? Try going through the intersection on red light and see if you get a
photo in the mail from your friendly DMV. ;-)

Cheers,

Pete

 

motion detector for the light. to detect pedestrians perhaps?

 

In the UK it would be vehicle motion detection to hold off
changing to pedestrian mode so that pedestrians would
not be able to get immediate access while vehicles were
in view - otherwise the lights can change in their favour
just about straight away.