The general speed limit tolerance has been 10km/h for automated cameras, however, according to the police, this has been reduced and they are remaining tight-lipped about what the actual tolerance is. There is no official tolerance used by road police and they have the power to prosecute for as little as 1km/h over the speed limit, so you should aim to keep below the speed limit.
Areas around school zones have a lower tolerance of 4km/h. This is because school zones are signposted at 40km/h and a 10km/h tolerance would simply allow drivers to maintain a speed almost that of the urban national road limit.
During holiday periods police have previously announced that the tolerance is reduced from 10km/h to 4km/h nationwide or in specific regions, but for all we know, the tolerance might now permanently be somewhere around 4-5km/h.
Speedometer tolerance
Vehicle speedometers are deliberately inaccurate, overreading by several percent. It’s not uncommon for a car that reads 55km/h on the speedo to be doing 50-51km/h. Therefore that cannot be used as an excuse for speeding.
There are many GPS apps for your phone which will give you a readout of your speed accurate to around 1km/h.
Why is having a speed limit tolerance common sense?
The speed limit tolerance is a common sense acknowledgement that making drivers nervously check their speedo all the time takes their eyes away from the road. Road safety advocates might say that if you can’t maintain a constant speed then you shouldn’t be driving, but that ignores the reality that many drivers (who are otherwise safe drivers) do find it difficult to maintain a constant speed and might fluctuate +/- 5km/h around their desired speed for a number of reasons, such as the road’s gradient, or inattention. Even many cruise control systems are variable within a few km/h because they are reactive to changes in gradient, not predictive of changes in gradient.
Even vehicles with speed limiters, e.g. trucks limited to 90km/h, can exceed the speed limiter’s speed.
Darren has written over 3000 articles about driving and vehicles, plus almost 500 vehicle reviews and numerous driving courses. Connect with him on LinkedIn by clicking the name above
