Vinnie S. wrote:

No they don't. The speed limits signs or laws do not say 55 or 65, +/-
10%.

That is nothing more than the descretion of the cop that tickets you.

Go read ORS chapter 810 sometime. It's up on leg.state.or.us. It does work
that way in Oregon. And as said before, save for a few miles of interstate
or a few well-travelled blocks of narrow secondary streets, Oregon has
never had speed limits. Posted speeds, yes, in which you're allowed to
drive faster if conditions warrant (on a clear, sunny day with dry pavement
and light traffic with a posted speed of 70, a cop pulling you over for
doing 85 will have a hard time getting a conviction in court unless it was
a LIMIT 70 and not a SPEED 70 sign and the cops know this).

Oregon and Washington both give 10% margins for differences in speedometer
calibration because very rarely are speedometers spot on. You could easily
be doing 59 with your speedometer reading 55. The speedometer in my 1995.5
Kia Sportage reads 62 when it's doing 60, my roommate's 2000 Ford Ranger
reads 57 at 60 MPH. If you got a ticket for doing 1 MPH over the speed
limit, and you didn't fight it in court, you're a moron, here's your sign.

--
Paul Johnson

http://ursine.ca/~baloo/