The electronic signs designed to inform motorists in Chandler, Arizona of exactly how fast they are driving have been displaying clearly erroneous speeds. To date, the city has spent $295,587 buying a set of sixty-four SpeedCheck signs which use the same type of K-band radar used to ticket motorists either using hand-held police units or speed cameras. Accuracy problems with the police radar units, however, are not on public display as is the case with Chandler's bright new LED signs.

The manufacturer of the SpeedCheck signs explained to the Arizona Republic newspaper that misaimed sensors, neon lights and other road signs can all cause faulty readings. The radar signs are meant to be a friendly reminder to drivers, so high readings do not result in citations.

That is not the case, however, at a dozen Chandler intersections where upgraded red light camera systems will also begin issuing citations for speeding on July 24.