Recently took a trip out to Hill End, NSW, a place that I'd once lived at in my younger years.
I saw this sign, which I'd have photographed had I had the camera with me, (this is courtesy of 'Panoramio' and Google).
which surprised me as cars and trucks have been using the Bridle Track for near a hundred years and I often drove over it in very ordinary and not powerful rear drive vehicles.

I'm not familiar with the Bridle Track, but its condition may of course have deteriorated since you drove it in your younger days.

Or, with a growth of tourism, there may be more drivers/visitors coming to the area who are unfamiliar with the track, and who have only urban driving skills. What may have changed, in short, is not the attitude of the council but the competence of the people who might use the track.

Or, it may simply be that standards of signage have changed. A good deal more thought and resources goes into the design, layout, etc of road than used to be the case; this includes a much greater use of signs, which in turn leads to an exectation that if there are hazards, they will be signed and, if they are not signed, there are no hazards. The result is that, if the track is, e.g., subject to flash flooding, then there needs to be a sign to say so.

Nannyism? Possibly. On the other hand, accident rates (expressed as accidents/injuries per kilometer travelled) have fallen significantly as more effort and resources has gone into road design and management. So, if the state is nannying us, it may be that the nannying is paying off in terms of protecting us.

Oh, and one other possiblity; the signage could be due in part to pressure from recreational 4WD users, who want to discourage other motorists from using the track, so as to leave it as much as possible to them.

That is certainly a lot of warnings, although its a good thing that less people are getting injured, our tolerance of hardship has diminished to.
I've noticed that now kids have less adventurous playgrounds and rules disallowing climbing and jumping etc they are much less confident about trying new physical challenges. I think it leads to laziness actually.
It may be a bit of a jump from the original topic but we can follow this nannyism of avoiding hardship to new food patterns. Grapes with seeds are rejected by many kids, and the peel on apples to and bread crusts of course. They are considered too much hard work to eat as they need lots of tiring chewing. Mostly seedless grapes are all that's available in the shops now.
Not much help in the fight against obesity and colon cancer one would think!

The crossing at the Turon River, low water.



and the Track around Monaghan's Bluff, 100 feet or so above the Macquarrie River; speed limit 100 k/h
(Both pictures Panramio,Google)