Keith, at 16:53 on Jun 07 1995, you wrote to Bill Grimsley...

BG> Caveat, I've never tried this, so you may need to be prepared to go to
BG> court if the copper books you anyway (unlikely, I'd suggest), and you'd
BG> then need to bone up on your doppler-shift theory in order to impress the
BG> magistrate.

KR> i'll remember that, may come in handy one day. perhaps you could ask
KR> your copper mate a question that has puzzled me for some time.

I've just gone one better, and spoken with the top dog (and a bloody
helpful fellow he was too - Snr Sgt Greg Wesling of the Traffic Branch).

KR> with the sideways looking radar traps,

You mean the Fairey slant-beam radars, presumably.

KR> how do they calibrate the angle that it is set at to the road? as doppler 
KR> can only measure the true radial velocity, the speed measured will be lower 
KR> than actual, and it will need to massaged to give the true value. for this 
KR> the angle of the beam to the direction of travel is critical. 

Yeah, I see your point, and it's a highly valid one.  According to Greg,
the angle is indeed critical, and must be precisely 25ø, no leeway at all. 
This is checked by driving a police car with a certified speedo (done every
60 days), and the indicated speeds must be within 1Km/h, otherwise all
readings are invalid.  Furthermore, under the Qld MT Act (Section 86e),
there is an official 10% tolerance allowed (not unofficial as I'd always
thought), which means that you will NOT be booked for any indicated speed
less than 10% in excess of the posted limit (i.e. 67, 89, and 111
respectively in 60, 80, and 100 zones).  Although the ADRs only allow for a
6% speedo tolerance at 100km/h, the Traffic Act is far more generous with
its 10% leeway.

And who said the police weren't helpful?  |-)

BG> I have also been reliably informed about this very same piece of road, by 
BG> a copper friend of mine who is still looking for this "lunatic pommy 
BG> bastard with a Corolla and NSW plates".  |-)

KR> why should that affect me? i am a lunatic ex-pommy bastard (an
KR> australian by choice not by the location where my parents got randy (:
KR> ), and the vehicle in question had qld plates.

Doesn't matter, that's close enough.  You're nicked!  :)

Regards, Bill
@EOT:

--- Msgedsq/2 3.10 alpha