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From: john@newave.UUCP (John A. Weeks III)
Newsgroups: sci.electronics
Subject: Re: Police Laser Speedtraps?
Message-ID: <848@newave.UUCP>
Date: 2 Jun 91 20:37:51 GMT
Article-I.D.: newave.848
References: <42808@cup.portal.com> <1991May31.135308.27239@msuinfo.cl.msu.edu>
Reply-To: john@newave.mn.org (John A. Weeks III)
Distribution: usa
Organization: NeWave Communications Ltd, Eden Prairie, MN
Lines: 37

In article <1991May31.135308.27239@msuinfo.cl.msu.edu> mackay@eecae.ee.msu.edu (James F. MacKay) writes:
> CPS@cup.portal.com (CHRIS PATRIC SMOLINSKI) writes:
> > Some of us at work were speculating on just how those new police speed
> > checking systems work - the ones that use lasers.  

> At a presentation about 2 years ago, a man (I forgot his name) said
> his company had working laser systems but for stationary police only.
> They would not work while the officer was moving.  Have they fixed
> this problem?

The Wisconsin State Patrol has been using an optical system since 1980.
Their system requires the patrol car to park in a pre-specified spot
and aim the optical system at a specially installed delineator post
in the median strip of the highway.  The delineator post has an orange
reflector on it.  The distance from the optical emitter to the reflector
is critical and must be recalibrated on a regular basis.

The State Patrol in Wisconsin also operates weekend speed 'comando' teams
that set up temporary optical speed measurement ranges in areas that
are targeted for enforcement.  They normally have one person operating
the speed reader with a camera to record the evidence, and up to 8 squads
to make the arrests.  They can issue several hundred tickets in a shift
thanks to the hot foot motorists from Minnesota and Illinois (states that
don't enforce speed limits) who rely upon radar detectors.

Wisconsin has also experimented with 'Electric Bridges', bridges that have
instrumentation built in to record vehicle weight and speed.  This systems
works well on highways with lower traffic volumes because the readings are
accurate only when one car at a time is on the bridge.  I hear that this
information is used mainly for traffic surveys and rarely for enforcement.

-john-

-- 
=============================================================================
John A. Weeks III               (612) 942-6969             john@newave.mn.org
NeWave Communications, Ltd.                        ...uunet!tcnet!newave!john