Speed Detection - 2 circles mounted on rear window of police car

[richsn]

Drive to Vegas:

I was travelling in the middle lane (3 lanes) amongst ~20 cars. I was driving fairly fast (~90) the flow of traffic was ~80-85. As I was driving I could see a couple of police cars about 100 yards ahead in the hard shoulder so I put the breaks on and slowed down to 70. All of a sudden the 2 police cars pulled out and followed me and another driver who was also driving at quciker than the traffic flow.

The police officer was professional and told me how fast I was going before asking me how fast I thought I went. I was immediately issued a ticket for driving at 90 and he informed me that I could appeal the ticket via mail or through a court appearance. When I informed the officer I was driving at 70 he said that I was driving 90 and then slowed down before passing. He then went on to explain that the 2 white circles in his rear window are what detected my speed, I had no qualms as I knew the process for appeal was via court.

What I would like to know is how did the radar pick me out in a group of cars in bright sunlight when I was changing lane? Is this new technology and what are the limitations of it?

Regards,

Rich

[richsn]

please ignore this thread. Posted incorrectly

[Joeyd6]

Double posted in Ask-a-Cop. Closing this one!