So gone are the days where a car can slow down near a speed camera and and, then later, when out of reach, speed up past the speed limit again.
How the PTP camera works is as follows:
- Over a stretch of X metres (let's call this stretch point A to B) there will be 2 cameras, one camera at point A and one camera at point B.
- If the speed limit is Y, the cameras will already know how long it should take you to get from A to B. Say T minutes.
- However, if you slow down at A, speed up, and then slow down again at B, you will still get a fine if the time it takes you to go from A to B is less than the time it would take a car to get from A to B at the speed limit Y (T minutes).
So for example, say you are driving along the Hume Highway from Cabramatta to Liverpool.
Say the speed limit is 80km/hr for the whole stretch (a bad example as there probably will be traffic lights - but assume there are no traffic lights).
Say that there is a PTP camera at Cabramatta where you start, and a PTP camera at Liverpool where you end.
If it should only take you 5 minutes from Cabramatta to Liverpool at 80km/hr, but you only took 3 minutes to do the stretch, then it doesn't matter whether you slowed down at the PTP cameras - so long as your overall time was less than 5 minutes, you'd be booked.
The logic being of course, that you must have sped up to reach Point B in that period of time.
Apparently tolls use this feature too but probably do not need to use it so often as the highway is usually jammed.
What an interesting, cunning and ingenious idea. It will surely earn extra revenue for the government if implemented all over the shop.
(I overheard this all from a colleague at work.)