Today while waiting for a passenger train in front of me to clear up so the red in front of me would finally go green, I was looking at the route ahead on the map and saw this symbol which I had not noticed before.
I think it's been there for a long time. I've noticed it since Boston sprinter I think but don't know/remember if it was a thing before
They started appearing with the first preservation updates when level crossings began to work properly after SEHS’s release. I believe they only show operational ones where the barriers move but I could be wrong.