The speed limit for heavy vehicles on the open road is 90km/h, but the open road speed limit for cars and motorbikes is 100km/h (or 110km/h on selected stretches). This means that trucks could exceed their speed limit by up to 29km/h (i.e. 119km/h) before getting a ticket from a fixed speed camera.
Obviously, in a 50km/h zone, a truck has the same speed limit as a car (50km/h), therefore no differentiation had to be made, but on the open road, some truckers were acting with impunity and flouting the speed limit without risk of being caught.
The older fixed cameras only managed to issue 433 tickets to truckies driving at more than 90km/h out of 611,712 issued for speeding to all drivers; a further 1632 tickets were issued to heavy vehicle drivers by other means.
However, newer cameras can measure the size of the vehicle as it passes. Is this likely to result in false positives? There are some large vehicles such as the Dodge Ram and some larger class 1 box body trucks, but police haven’t said how accurate the measurement of a heavy vehicle is; presumably there would be human intervention in each case to determine whether a fine should be sent.
Many trucks now have GPS monitoring and their drivers (or the drivers’ managers) get a report of overspeed events and can act on that information.