I don’t remember reading about or being told about anyone being involved in a serious accident due to trespassing on the railway either and I have been in Poland a long while. I have been on the train a couple of times when we have smacked deer though which maybe you could argue wouldn’t get onto the line had fencing existed.
Been on a train at least 2, maybe 3, times in recent years that has struck deer, on one of my local lines (Redhill-Tonbridge). Blood, damage, delay. I do a lot of walking in the area and it is clear that many of the numerous foot crossings would present no obstacle to an agile deer.
Times have changed in the UK. 50 years ago I would cycle with my school mates to a bridge or tunnel and watch the trains, mess about on the line, put pennies on the rails etc. On one sunny Sunday (when trains were running) we counted well over 20 other people doing likewise, including adults with kids, a group of teenagers walking right through the tunnel, and a gang of Hell's Angels who parked their bikes and walked down the line, with their girls, and disappeared into one of the old platelayer's huts. I wonder what they were doing?
Of course it was "fenced" but then just post-and-wire to fulfil the legal requirement, no obstacle at all. Now it's security fenced, some is 3rd rail electric, and any hint of trespass results in standstill, current off (if there is one) and mega delays, with passengers muttering "just run the b*gg*rs over". Ironically on one occasion the trespassers were clearly East Europeans wondering what all the fuss was about!
Whatever its drawbacks, I do relish the relative freedom to roam in continental Europe compared to fenced-in Britain.
Edit: Thanks
@Gordon for the clarification re-France. Nice picture!