alt Hacker NewsThe saying/claims in the last 20 years or so is that London has the highest ratio of cameras to people in the world, through looking at what seems more correct statistics it is only the 12th most dense camera city in the world. how well that translate to the rest of the country is much less talked about.
Here in Sweden, people walking on the rails without permission is a fairly common problem, which cause almost 4k hours of accumulated delays per year. For people who often travel by train, the announcement of reduced speed because of the system has detected people on the tracks are one of the more common ones, only second to the catch-all announcement of "signal error", which simply mean the computer says stop for a reason that the driver don't know or don't want to say.
When it comes to suicide prevention on bridges, it is not just the big bridges. Suicide by train is a fairly talked methods in the news as a work hazard for train drivers, and the protection here is for small bridges that goes above the track. Similar issues exist with bridges over roads and highways. Those methods are to my read of the statistics more common than the movie version of a person jumping from a suspension bridge.
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.