Having a trip sensors to trigger emergency responses seem to be the correct approach to dealing with suicide concentration points. You could build an impenetrable barrier but would simply shift the problem. But having sensors means that emergency services can responds and hopefully prevent a death and give the person the appropriate care. If there are 50 people committing suicides there each year then it seems like a very appropriate solution.
In contrast Melbourne spent $20 million on "unclimbable" safety fences on the Westgate Bridge. Furthermore government is now being sued because they didn't do this early enough. While I'm no expert I would think that all this is doing is shifting the problem: