On Fri, 11 Feb 2005 14:45:50 -0800, Paul Johnson
wrote:

Dave Hall wrote:

Most car speedometers are not so accurate that a 1 MPH difference is
all that hard to believe. Just putting one size larger tires on your
car can make that difference.

Well, you're supposed to get your instruments recalibrated after changing
tire size.

Yes, you probably should. But periodic speedometer calibration is not
on the list of "maintenance" items in the owner's manuals, nor is it
required as a part of (At least in my state) annual inspection. I'm
not even sure if anyone (other than the dealer) can even perform such
a service. It's clearly not something they advertise.


But differences as much as 5 MPH can happen depending on tire
pressure and road conditions...I've yet to see a speedometer read the right
speed driving on Oregon's notoriously rutted freeways in the rain (probably
because you're forced to hydroplane along the lane, which is why the locals
*will* get aggressive towards tailgaters, though the Californians usually
don't get it until they slam into a wall or the car ahead of them
approaching slower traffic hiding in the road spray of the vehicle ahead
because they're following too close).

People have fought a speeding ticket on this basis and have won.
That's part of the reason why Pa. gives some leeway. Most cops don't
want to have to appear in traffic court when the chances are good the
case could get thrown out. However, it's a lot harder to make a case
for speedometer inaccuracies when you're 10 MPH or more over.

I used to have to deal with police a lot when I was a security officer, and
at one site, the worksite's driveway was a common spot for police to set up
speed traps. The cops don't even bother radar cars until they see someone
moving considerably faster than surrounding traffic, radar the overspeed
vehicle for evidence, and just use the posted speed as something to
estimate a fine from.

That's pretty much what they do here as well. In the state of Pa.,
RADAR is only allowed to be used by the state police (You actually
have to be "certified" to use it). The locals use VASCAR, which is why
there are so many white painted lines across the road (Which also
gives alert drivers a heads-up as to where the speed traps will
usually be).


They seem to radar everyone in areas where there are actual speed limits
when I see a speed trap in a limit zone. Though I never see anybody pulled
over, everybody just slows down for the speed limit and then drops the
hammer down when it goes back to a posted speed a few miles down the road.

That's the whole basis of the "Smokey Reports" that run across the CB.
At first the cops were ****ed at this method of circumventing the law
(As they are with flashing headlights). Now the cops use it to their
advantage. Sometimes they park an unmanned car near a busy highway and
let the CB'ers pass the word, and everyone slows down, which is all
they wanted anyway.

Dave
"Sandbagger"