The official number has never been revealed, but a new report this week suggests the New South Wales Government will soon do away with its margin of error on speeding offences.
A new report published by the Sydney Morning Herald claims that a leaked cabinet document, obtained this week but dated December 9 last year, points to a decision to put an end to the "internal and undisclosed tolerance" for speeding vehicles.
According to the document, the existing margin of error is a 3km/h leeway beyond the alleged speed recorded by fixed and mobile 'safety' cameras.
The move has been criticised by an unnamed senior Sydney police officer who told Fairfax that the change left motorists vulnerable to fines simply by fitting new tyres, potentially throwing the reading of their speedometer out by a few kilometres per hour.
It is unclear when the new rule will come into effect, or if it has been applied already.
The changes are tied to the introduction of digital safety cameras in New South Wales early last year, which the NSW RTA claims are capable of providing a more accurate recording.
Debate over the margin of error for speeding fines has raged for years, with the 10 percent tolerance allowed by the Australian Design Rules changing in 2006 from a vehicle's speedometer reading, to the actual vehicle speed.
In Victoria, the official tolerance was revealed by the State Government in 2007 to be 2km/h for fixed cameras and 3km/h for mobile speed cameras. A discretionary tolerance can also be applied.
Photo by Robin Papa.