>PJH wrote:
>
>> Just wondering why a radar detector would be activated at traffic
>> lights in that case?
>

Possible reasons,

Some traffic lights use Ka band photo radar to monitor red light runners and
issue photos and tickets.

Also, I believe, some traffic lights are controlled by X-band sources
located in firetrucks for controlling the light green upon the emergency
vehicles arrival at the intersection.  (Some other systems use modulated
strobe-like lights).

X-band and sometimes K band door openers located in the area.

Other radar detectors causing in band signals.

Craig R. Autio