We Can't Drive 55

By Rachelle Bowden in News on Oct 11, 2006 4:52PM

Speeding? Got a lead foot? Your pedal to the metal? You might want to slow down. Chicago police have a new and more accurate way of catching you.

It's a new speed gun called Lidar that uses laser instead of radar to catch people speeding. Police say it's the most accurate speed gun they've ever used and that eventually it will even be able to read license plates. And easy to use? Whew! Is it ever ... Sgt. Greg Reynolds says all they have to do is "pinpoint which car we would like to get the speed from by looking through the viewfinder it shows us on our screen."

Not to get to techie, but here's how this thing works: A laser emits a highly focused beam of invisible light. Instead of finding a vehicle's speed by measuring its doppler shift, like police radar does, the laser Lidar calculates speed by observing the changing amount of time it takes to "see" reflected pulses of light over a tiny amount of time.

So, be on the look out. And slow down. Or, at least go to this site and read how to defeat Lidar and get a new-fangled radar lidar detector.

Image via laseratlanta.com