[Scan-DC] Off -Topic - Speed Camera Technology?

[Doug Kitchener]

I realize we're getting off-topic here and I apologize.  However, lots of folks here have a lot of knowledge about technology, and I haven't found the answer to this elsewhere, so here goes:  Does anyone know what technology the local speed cams use to distinguish speeds?  (Do they use radar / will a radar detector detect them?)  Feel free to reply off list - thanks, and again, my apologies to those who may be growing weary of the topic.

DK