The law that you linked says that drivers aren't allowed to drive at an unreasonably slow speed, and defines that to be (for highways, with good weather, and just on the leftmost lane) 80 km/h.

It doesn't say that the speed limit is a target, or that you're supposed to drive at or near it.

Yes, but it's how we're taught at driving school. I think it's written down somewhere but can't find it at the moment, so the article I linked to is the closest I could find.

> ...but it's how we're taught at driving school.

It doesn't matter. People have all kinds of things they are taught about driving from their parents, instructors, and even official documents that don't carry legal weight (e.g., a highway patrol website).

Even when these types of ideas are good ideas, they aren't binding and you can't count on others to follow those rules. The only true rules of the road are the subset of the laws that are enforced; where enforcement might be done by law enforcement officers, civil judges, or insurance company adjudication processes.

In the US it’s legally a max. I have seen — although rarely — entire lines of cars pulled over and ticketed for speeding on an interstate (limited access, multilane divided highway, max speed 65-70 mph (104-112 kph)) Driving too fast for conditions, is a different fine, so if it’s foggy and you’re going the posted limit, you could also get fined.

You can get ticketed for driving too slow, but I’ve never seen it. I’ve only seen a minimum speed posted on an interstate (45 mph (72 mph)), but conceivably you can get ticked anywhere for impeding the flow of traffic.

> You can get ticketed for driving too slow, but I’ve never seen it.

I have (very gently) forced a car off the road once in Germany with the police on 112, a very elderly gentleman was doing 30 Kph on the autobahn and caused one near miss after another. Police came and helped him to get home, we talked for a while and it turned out that it was his first trip in a long time to go and see his sister in another town, he'd gotten lost and was frightened out of his wits by all the traffic zooming by.

I don't know how it ended, he probably kept his license because clearly there was no officer around to witness the event but I'm pretty sure he avoided the autobahn after that.

In Australia (I left 15 years ago) it was stated that you were required to drive at the _maximum_ speed that met the conditions:

- not exceeding posted speed limit

- appropriate for environmental conditions

- your ability to safely control the vehicle

And failure to do so could be fined.

This is incorrect (which is lucky, because it would both be extremely unreasonable and impossible to enforce). You can only be fined if you are driving so slowly that you are causing an obstruction.

Citations:

NRMA: https://www.mynrma.com.au/cars-and-driving/driver-training-a...

Australian road rules: http://www5.austlii.edu.au/au/legis/sa/consol_reg/arr210/s12... -- key paragraph: "a driver does not unreasonably obstruct the path of another driver or a pedestrian only because [...] (b) the driver is driving more slowly than other vehicles (unless the driver is driving abnormally slowly in the circumstances)." (Note that these rules form guidance for the States, so there will be per-state differences -- see below)

Western Australia is the only state which explicitly defines "too slowly", it's 20km/h below the limit, and it only applies to freeways. https://www.whichcar.com.au/car-advice/is-driving-slow-illeg...

Any idea how that worked out in practice?

Anyone can claim their ability to safely control the vehicle would have been impaired at $cited_speed + 1 km/h.