By Nick Aziz
Thursday, Apr 27th, 2006 @ 2:29 pm

A new type of speed trap developed by the University of Tennessee could detect the speed of a car based on the sound of its exhaust as it passes. According to a report in the 2548 issue of New Scientist, the system uses microphones to record the sound of passing cars, and then a computer program isolates the various vehicles. The program then calculates the vehicle’s speed by measuring the exhaust sound’s Doppler shift. According to patent filings, development was funded by the US Department of Energy. Unlike radar systems that can be detected by dashboard-mounted devices, this sound-based system would be undetectable.