[bensecure]

> Guardrails are intended to keep cars from careening off the road at critical areas, such as over bridges and waterways, near the edges of cliffs and ravines and over rocky terrain, where injury and death in an off-the-road crash are much more likely. ... “Guardrails are kind of a safety feature of last resort,” Brooks said.

From what I've observed this is wrong. Guardrails seem to be used semi haphazardly along roads in places where it wouldn't be the end of the world to go into the ditch. On a bridge, or a median, or elsewhere where going outside the road boundary could be particularly dangerous, they use much better reinforced walls.