Speedo inaccuracy?

Is there any allowance these days for speedometer inaccuracy with
speeding offences? E.g, do people ever get booked for 101 in a 100
zone? How accurate must a speedometer be to be legal for rego?

I'm mainly interested in the law for NSW.
I couldn't find the answer on the RTA or NSW Govt legislation websites.

(It's just a hypothetical question -- I haven't been booked.)

 

In aus.motorcycles on Thu, 13 Nov 2008 22:56:12 GMT

You are confusing three things.

One is the federal law as pertains to what a new vehicle must have to be
sold new in Australia, one is the law as is required for registration
of a vehicle that is no longer new, and one is the state law as to how
fast you are allowed to go.

The federal law says the speedo is allowed to read up to 10% faster
than you are actually going I believe. I think it might be allowed a
3% slower reading, but I couldn't be arsed looking up the ADR, and it
doesn't matter a damn anyway, see below.

If the car was required to have a speedo fitted when it was sold new,
then it must have one fitted to be re-registered. And some rego places
will insist it works - as in the needle moves when the car does.

It isn't tested for accuracy, that's not in the rego requirements.

The state speedlimit law doesn't *care* about your speedo. It cares
about your speed.

It is up to you to determine that speed. You can rely on the speedo,
you can rely on counting lamp posts, you can rely on a pushbike speedo
fitted to the front wheel, you can rely on luck. But you can't get off
a speeding fine because your speedo was not accurate.

Were you doing the speed the prosecution says you were? If so, then you
are guilty and you pay your fine. Why you were doing it is irrelevant.
"My speedo told me I was legal" is as valid an excuse as "The voices
told me to."

Moral of the story? If you aren't sure your speedo is accurate, get
it tested by an instrument tech or test it yourself with a GPS unit.

If you want to avoid fines, then your best bet is to aim to travel at
5km/h below the limit, rather than aim at or above it.

Zebee
- who has tested her speedos via GPS and via a bored and therefore
friendly cop at a speed trap, because Italian speedos are only
there for regulatory purposes.

 

Hypothetically, you don't need a speedo for registration or roadworthy
certificate
It is the responsibility of the driver to maintain the correct legal speed
and if your speedo is out, then bad luck if you get booked
Some cars will have a 2% tolerance, then another car off the same
production line will be 10% or even more out of whack.

But getting back to a camera's tolerance, there is usually a 3% tolerance
between the alleged speed and the actual speed you get charged with.
You would be highly unlucky to be charged with 101 kph, even if your
detected speed was 105 kph

 

What Zebee said plus they have to book you for 3kms less than the
radar indicated speed if you are below 100 km/h and allow an extra km
for each ten kms over 100. E.g. if they read 124 kms/hr then they book
you for 119.

Theo

 

If your vehicle came new with a speedo, you are required to have it
still there and operating. If your vehicle is less than 100cc (I
think) and it didn't come with a speedo from new, then you don't have
to fit one.

Theo

 

I think that's more specific to the operating tolerances specified by
the manufacturers of the speed detection equipment. eg in Vic on a
speed camera fine they will knock 3kph off the detected speed but if
you're busted by a car mounted radar unit they only knock 2kph off.

Nev..
'07 XB12X

 

bugger, there goes my defense..

mh

 

A lawyer told me that there is a =-5% speedo tolerance and a further
+-5% for the external measuring equipment (radar, camera, whatever)
In effect, if your actual speed (not the one measured by the speedo or
the camera) is, say, 110.25 in a 100 zone, then you are OK.
Problem is, your speedo is +-5% inaccurate, so how do you know your
actual speed? Same principle applies to the camera.
Better off staying on the speed that you know is legal, or cop the
fine in good humour (if you haven't already been booked)

 

OK. I thought this was speicfied in an Australian Standard, which are
great because you have to pay to read them.

Theo

 

I mean if you have

 

Must be different in Vic then as my ticket said measured at 108,
booked for 104, in a 100 zone. $128 please.

Theo

 

The problem with assuming that people who are in a particular industry
know everything related to every single facet of that industry is that
"lawyers" will tell you stuff that lawyers have no reason to be an
expert in and you will believe that stuff as gospel.

I bet it didn't say please. How far out is your speedo?

Nev..
'07 XB12X

 

You're singing to the choir, of course, but that's what I was told.
There's an implied grain of salt in my post, but it was well hidden.

That's the nub of the matter. Tolerances depend on technology, quality
of manufacture, opinions of the operator, the time of day, how the
entrails of the chicken lay... As I said, the best shot that you have
is to stay on or below the posted limit as shown on your albeit
slightly inaccurate speedo.
Otherwise, do what I do, and smile as you pay up. Just watch those
points though - they creep up on you...

 

Don't believe everything you're told by lawyers

JL
Or people pretending to be one at parties

 

spoil sport!

Moike

 

Or architects

Yes

 

Yeah that's the vic standard operating procedure, NSW don't do it(for
example) - not an Aussie std though I'm 99% sure. Done to prevent
challenges about the accuracy of the radar IIANM

JL

 

Oh I don't believe ANYTHING I'm told by a cop until I have some sort of
independent verification (and only then if it can't be tampered with)

Or to plant evidence or just plain lie.

Mmmm only for the fact that half the police force would be sitting in a
courthouse waiting room waiting for the case to be called - less on the
roads.

JL

 

Been changing jobs at parties Moike ?

JL
FWIW I know lawyers who pretend to be anything but at parties

 

However, in the case of a motorcycle, unlikely. I remember reading a
test of the accuracy of the speedos on a variety of motorcycles a couple
of years ago. In every case the odometer was sufficiently accurate
(within 2%, I think) but, except for two BMW models, the speedo wasn't,
registering anything between 3% and 12% *faster* than the actual speed.
Not one registered slower than the actual speed.