Melbourne to Sydney took us about 13 hours on a drizzly winter day, driving in a very relaxed manner at or just under the speed limit along the Princes Highway, with a couple of stops.
The maximum speed limit is 110 km/h, and on the undivided sections it is 100 km/h.
Despite the single lane on the undivided sections, no one really dawdles. Everybody, including cars pulling trailers and even goods vehicles, drive at at least 90 km/h (there is a minimum speed limit rule that applies too, and one is likely to be warned by the cops for driving too slow and endangering other traffic). Overtaking lanes are set up every few km - no one generally crosses the unbroken lines otherwise.
What amused us no end was these signs everywhere. These deserve to be used and adopted just about everywhere in india! I was to find out later that with a large migrant population, especially people from countries where *Keep Right* is the rule, a lot of drivers do make the cardinal error of going on to the wrong side of the road in Australia, where traffic keeps to the left.
Speed cameras on the highways are very frequent, and motorists are warned well in time. It's either police cars parked to the side of the road, or automated speed cameras set up on a boom across the road.
Of course, there are other compelling reasons for reducing speed too - like kangaroos. Hitting a fully grown kangaroo at 100 km/h can write off your car, apart from more serious consequences! My co-trainee in our Low Risk Driver Training class reported having totalled his car in the process of coming too close to a kangaroo a few years ago.
It was a long weekend coming up, with the weekend combined with the Queen's Birthday (celebrated on the second Monday of June every year), and everybody was on the road, heading to the coast for their dose of fun on the water. Despite that, for us battle-scarred souls from India, the highways appeared almost deserted!
There's strong focus on preventing drink-driving on the highways, and signs such as these are frequent, as also are random breath check stops.
Also interesting is the focus on driver tiredness, with constant reminders through signs like these that a break and / or powernap is better than driving while drowsy. There are also plenty of well-appointed designated stopping points on the highway, with clean toilets in the parking area, even though there are no shops etc. there. The local council maintains these stops.