They shouldn't raise the speed limits at all - any faster and you won't do a proper job polishing the turd (which is the subject of this thread).
Seriously, regardless of how new a car is or how good its brakes and tyres are, there are still limits to driver reaction and physical stopping distance. Furthermore, the whole reason why schools have a 40km/h zone around them isn't because cars are incapable of stopping. It's because kids can run out unpredictably and a car doing 60km/h is going to do a lot more damage to the kid than a car doing 40 km/h. Same goes for high pedestrian areas, and residential areas.
On the freeways I can understand raising the speed limit a bit, but road markings, reflectors and signage needs to be drasically improved and lanes need to be widened more. While I'm doing 95km/h, a truck passing me doing 100km/h doesn't upset my car or the caravan a whole lot. A truck at 130km/h though whallops my caravan (in the same direction). Even worse, an oncoming truck doing 130km/h (in the NT) while I was doing 125km/h was a major issue - that's a combined oncoming speed of 255km/h and the buffeting was quite a drama, even when I expected it and moved as far over as I dared.
I don't think they do most of the speed limits with how capable a vehicle is in their minds, nor the revenue they can raise.
They can't raise revenue if nobody's breaking the law!
