Re: Right, $50 of bars will stop a 4000lb car going 74mph.
>So you deliberately create a slightly larger hazard in the road on either side leading up to the crossing. That way, no-one can actually reach the crossing unless they are also able to cross it.
> (Or has some sociopath got a patent on that idea...)
Hardly. It would just be a slightly larger speed bump. I have also sometimes seen horizontal striped bars hanging from chains before unusually low bridges or underpasses, in the hope that the driver of a tall vehicle would at least hear the CLONK, before hitting the bridge....