I find speed cameras interesting. This is the first time I've seen a fine for an average speed camera, so I thought I'd check it out.
. https://forums.whirlpool.net.au/archive/2779347
In the post by abbots the fine stated, allowed time 878s and their alleged time was 817s. The section of road was Forrest Hwy s/bound Lake Clifton. They were fined with doing 117km/h where the speed limit is 110km/h. Given the speed limit and the time allowed, this gives us the distance of 26.827 km.
You can find the Lake Clifton PTP camera located here.
https://www.speedcameralocations.com.au/wa/?lat=-32.8951349&lng=115.7137058
The end PTP camera is located in Binningup.
https://www.speedcameralocations.com.au/wa/?lat=-33.1338527&lng=115.7210756
According to Google Maps the distance between these two GPS locations is 26.9km. which shows a close correspondence.
If we then work out what speed the person would need to be going to cover 26.827km in 817s, we get 118.2km/h. It is interesting there's a variation of 1.2 km/h.
The first thing I found interesting was the time is second is what is used to determine if someone is speeding or not. That actually makes sense because the two variable figures that are easily available is the time at the first camera and the time at the second camera. The difference is the time taken to travel the known distance. From the known distance and the time taken their speed can be estimated.
It should also be kept in mind; from what I've read; the distance travelled between the two average speed cameras is the shortest distance. I imagine this to be the line that cuts across lanes on curved sections of the road. If people speed and stay roughly in the same lane and not cut across lanes to use the shortest distance, they're in fact being a slight allowance because the distance is long, so they would take longer to do the distance.
The second thing is if someone is caught driving at 117 km/h, if they needed to slow down for other cars, then their peak speed is going to be quite a bit higher.
When using cameras the government usually provides an allowance, first for error in their equipment and second an unstated tolerance. The tolerance for the equipment is usually 2 o3 km/h or above 100 km/h 2 or 3%. The unstated tolerance might be closer to 6 km/h.
What we can see here is the person was booked for doing 117 km/h on a 110 km/h road so we now know the unstated tolerance is less than 7 km/h. Anyone who still thinks there's a 10% tolerance is probably in for some financial pain.
As more people share their speeding fine stories. the unstated tolerance will become more obvious. Each person has their own driving preference. I use my GPS to let me know the speed and usually drive close to that speed, but ultimately, it is how comfortable I feel the car is for the conditions. Others drive using the speedometer and others tend to drive a little over the speed limit believing they won't get fined, whilst others simply don't seem to care, or don't realise they're speeding. Fines are a way for the government to encourage people to comply.
Fixed and portable average speed cameras usage is growing across Australia so information like this person's fine is good information to know. Hopefully you've found it interesting.
Kelvin