LX protection:It's a visual barrier, not a physical barrier - and designed to break off if a motor vehicle runs into it.
Does the presence of boom gates actually have any physical effect, ie would a boom gate hold back a car (at a suitably low speed - high speed no way of course)? Or is the protection more of a mental one that encourages a greater precautionary response from drivers?
A signalling engineer in Victoria told me of a level crossing where there were a number of near misses or collisions with trucks when the LC was fitted just with lights, all blamed on "brake failure". As soon as boom barriers were in place miraculously there were no more brake failures, and no road/train collisions. So, anecdotally the visual barrier is effective.