Claustrophobic guardrails on roads

Has anyone else noticed the proliferation of guard rails along many roads around Brisbane in the past six months or so?

I travel along a few narrow roads, for example, Mt Crosby Road, and I have noticed that the road is being enclosed in a dodgem-car style protective rail of Armco fencing, for almost it's entire length. Fair enough if there is a steep drop-off or some hazard off the side of the road, but in places the road has been cocooned at the edge of the bitumen which leaves very little leeway should something go wrong, or as sometimes happens, a car breaks down and cannot be moved off the very narrow two lane road.

Armco rail has been installed on a few other roads I am familar with and I don't understand why.