People on tracks and suicide by train are, I suspect, way more common in London for us than elsewhere. I can't get solid figures though. But it seems to sit around 15k hrs of delays nationwide for people on tracks.

We had a big government inquest into suicide in 2018 which included asking national rail to justify it position and actions. Of the 30k rail bridges in the UK only the hotspots have any modern measures of suicide prevention; and the hotspots are mostly but not exclusively suspension bridges.

However, from your comment, I see that you might be meaning pedestrian bridges across tracks, which almost always have metal rails higher than an adult man here. Our older stone road bridges (which are very common) have thick and tall walls on the edge which serve a similar function if not as effectively.

However, I think to hark back to the original image and post - the bridge depicted is a train bridge going over a road. More like a viaduct tbh. Its highly unlikely that there is any normalised pedestrian access so it won't tank highly for assigning prevention and detection measures for either suicid, and its easily assessed from the busy public road so I doubt it makes the priority list for automated collapse detection.