I feel like this is something that's often neglected.
Just recently here in Finland there was a case where a cyclist died because a roadblock made of concrete was brought to the middle of a dark tunnel.
The goal was to block cars from using the tunnel, but for the summer the tunnel's lights were turned off. The cyclist hit the roadblock at a relatively high speed, was basically launched forward and pretty much immediately died on impact to the ground.
Now of course maybe the cyclist shouldn't have been going that fast, but the decision to bring a roadblock to the middle of a dark tunnel is also questionable. Maybe two roadblocks at each end (where there is natural light)?
I feel tunnels are much more dangerous than bridges. They're dark and the downhills leading to them encourage high speeds.
Link to the news article: (in Finnish) https://yle.fi/uutiset/3-12456122
Google translate seems to do well on the article: https://yle-fi.translate.goog/uutiset/3-12456122?_x_tr_sl=fi...
Although maybe concrete piglet/pig should be just "concrete roadblock"
edits: added the news articles