Scott en Aztlán wrote:
I've seen several of these devices attached to the street light poles
in Irvine, CA. Clearly there is some kind of radio inside the box, but
what is their purpose?

http://tinypic.com/6okknl.jpg

Are they attached to random street light poles, or are they at/near
intersections? And what streets are these on - which street was that one on?

According to the City of Irvine's website, the city's Traffic Research
and Control Center has various mobile, wireless cameras set up around
Irvine to monitor flow on major arterials and some other side streets.
Might that device in the image be related to that?

--
Robert I. Cruickshank
roadgeek, historian, progressive