Proper1 wrote:... and yes, I know you're kidding...
Oh no I'm not! 
The SWS program was developed in 1995 under the auspices of the Georgia Technical Research Institute and engineers from a consortium of mobile electronics firms including Bell-Tronics, Santeca Electronics, Uniden American and the Whistler Corporation. The SWS system employs the K-band (24.1Ghz) and can transmit up to 64 pre-programmed text messages to radar detectors made by a number of firms. The messages are transmitted by the use of small transmitters that can either be mounted in a fixed location or attached to vehicles. For example, a mobile transmitter could be attached to a school bus providing alerts to drivers about the location of a bus picking up children. The alerts can be received within 1.5 miles of the receiver in ideal conditions. A few representative alerts are: "right lane closed ahead," "train approaching/at crossing," "ice on bridge ahead," "expect 10 minute delay," and "police in pursuit." Uniden's GPS-RD with just about every bell and whistle including GPS, electronic compass, elevation and SWS retails for $229.
Several "serious" Radar Detectors are pre-programmed from the factory to warn a driver (by electronic voice) of the actual hazard ahead. Other "cheapo" radar detectors will still beep at the presence of an SWS alert, but can't tell the driver the details of the alert.
If Ontario Lawmakers would just embrace the potential for the GOOD that RD's could provide (rather than see them as a hinderance to ticket revenue), I have no doubt we would see a major improvement in road safety, at least with regards to the subject topic.
http://www.youtube.com/watch?v=c87qxDMT55c
(check volume if at the office!)
If I were a cop, I would pay the $229 out of my own pocket to have an SWS transmitter installed in my cruiser.
EDIT: My bad. The SWS transmitter isn't $229... the Uniden RD is.