Speedo accuracy - spin-off from QLD tolerances

[MAD]

I thought I'd start a new topic to see what views/facts/or otherwise are out there on this topic. I'm not going to cover every single detail, as I don't have the time or knowledge of all laws governing our lives, but I wanted to put forward some things that are common sense, and things that I know to be true and see where the discussion takes us.


Prior to 2006 the ADR requirements for speedometers fitted to the category of vehicles, that our family cars fall into, was that it could indicate a speed within +-10% of the actual speed, and were allowed to understate the actual vehicle speed.
100 could equal 90 or 110

In 2006 someone thought it was a great idea to disallow the understating of speedometers and change the tolerance based on a fandangled formula.

Originally Posted by MAD

ADR 18/03 says the speedo must read slower than actual speed and must fall within the following tolerance...

0 ≤ (V1 – V2) ≤ 0.1 V2 + 6 km/h; (V1 - indicated, V2 - actual)

Using this formula the maximum discrepancy between indicated and actual at the required test speeds can be as much as the following.

Indicated speed - actual speed - discrepancy
40 - 30 - 10
80 - 66 - 14
120 - 102 - 18

40 could equal 40 or 30
80 could equal 80 or 66
120 could equal 120 or 102



Now, on to the topic of things being illegal, and what constitutes breaking the law and being accountable, etc.

Ignorance is not an excuse.
We hear occasionally of a crime that has been committed where the person was found to have a skewed perception of right and wrong, to which a lesser penalty is delivered.
The lines between legal and illegal are very well defined in many instances. For example, you can't accidentally pre-meditate a murder, and you certainly couldn't accidentally hold-up a bank.
Knowing the difference between right and wrong and still choosing the latter is a willful disregard for the law.



On to our situation as motorists.

Exceeding the sign posted speed limit is illegal.
Maintaining your vehicle at a speed that is at or below the sign posted limit is the sole responsibility of the operator of the vehicle.
The tolerance given to drivers in VIC is 3km/h, plus the tolerance of the detection device. (2 or 3 km/h depending on the device)
Driving through a school zone at 120km/h is definitely breaking the law.

The best we can do as an operator of a piece of machinery, manufactured to a defined set of standards, is operate that piece of machinery based on the the standard of equipment fitted to that machine.



Let's start with a situation in a car manufactured pre-2006.
Zone - 110km/h
Indicated speed - 110km/h
Extremes of possible detected speeds - 99 or 121 km/h
Extremes of possible alleged speeds after device tolerance deduction - 96 or 118 km/h

The absolute best the owner/operator of this vehicle can do to drive within the posted limit is to base their speed on what the readouts supplied in that vehicle tell them. It is entirely possible that the driver of this vehicle could unknowingly exceed the posted speed limit.


Same situation, car made after 2006
Zone - 110km/h
Indicated speed - 110km/h
Extremes of possible detected speeds - 94 or 110 km/h (tolerance at 120km/h is 18km/h, so I'm assuming a little less at 110km/h and calling it 16km/h)
Extremes of possible alleged speeds after device tolerance deduction - 91 or 107 km/h


The absolute best the owner/operator of this vehicle can do to drive within the limits posted on the road is to base their speed on what the readouts supplied in that vehicle tell them. It is impossible for this driver to exceed the speed limit based on the readouts supplied in this vehicle.



Now, another couple of examples based on the same two cars above.

Vehicle 1 (pre-2006)
Zone - 110km/h
Indicated speed - 107km/h (is happy to drive a little slower to avoid a fine, but not so slow as to cause a major disruption)
Extremes of possible detected speeds - 96.3 or 117.7 km/h
Extremes of possible alleged speeds after device tolerance deduction - 93.3 or 115.3 km/h

A driver knowingly trying to avoid a fine has one delivered because the standards to which their vehicle was built allowed this to happen.



Vehicle 2 (post 2006)
Zone 110km/h
Indicated speed - 130km/h (wants to drive fast but doesn't want to lose license and 'knows' all speedos read little low)
Extremes of possible detected speeds - 112 or 130 km/h (assuming same 18km/h tolerance as at 120km/h)
Extremes of possible alleged speeds after device tolerance deduction - 109 or 127 km/h

The driver of this vehicle is knowingly choosing to speed, based on the readouts given in this vehicle, (willful disregard) yet it is entriely possible for this vehicles speed to be checked by a detection device and be found to fall within the legal limits of the traveling speed zone.



Let's look at some arguments to go with these situations.

Situation 1. No argument is recognised by the courts as the ADR's are not "Law"
How can this driver not be able to defend themselves when they were knowingly adhering to the posted speed limit?

Situation 2: No legal arguments needed, they're just an annoying slow driver that disrupts the flow of traffic on the <insert name here> Freeway.
Surely this situation has caused many accidents from the flow-on affects (most likely a nose-to-tail)

Situation 3:Very similar to that of situation 1, but slightly worse due the driver putting in extra effort to stay on the legal side of things.
How can this driver not be able to defend themselves when they were consciously driving below the posted limit.

Situation 4: Potentially no argument required as the driver believes he has escaped the long arm of the law and is thinks he is very clever because of it. So much so that he boasts to his friends that has done 15 trips from Melbourne to Kerang this year and always sets his cruise at 125km/h and has never been caught. He's even had police car's drive right past him and not been given a second look.
How is it ok for this driver to be knowingly breaking the law but it is impossible to be detected as such?


So it is not illegal to drive your car with an indicated speed higher than the posted limit, but it's possible to be fined while driving with an indicated speed lower than the posted limit.



Anyone see anything wrong with the picture here?