Friday, October 06, 2006

Near Raleigh, NC 20 microwave radars have been installed on a busy 27 mile stretch of I-40 from the Chapel Hill exit (US 15/501) to the Lake Wheeler Road Exit. That averages a radar every 2.7 miles (10 radars for each direction of traffic for 27 miles). All 20 radars continuously transmit and are intended to measure traffic flow, not catch speeders.

With so many radars so close to each other many radar detectors will be alerting drivers of the signals most, if not all, of the 27 mile stretch.

Police will also have to be careful when running a microwave speed radar. Two radars relatively close to each other and transmitting at or near the same frequency will interfere with each other. The interference should be detected by the police radar. However if the interference is intermittent it may be missed or not detected (missed or false speed readings). The traffic flow radars may be interfered with causing missed or false readings completely unknown to those monitoring traffic flow.

CopRadar