Who is responsible for putting up RR crossing signals? The RR, DOT, or someone else?
How do they determine if a flashing signal is needed or just the sign?
There’s a good chance I might be wrong, but as far as I know the railroad installs and owns the crossing signals that have to meet DOT specifications. As for whether or not they’re flashing signals, I think that all depends on the danger at that particular crossing. Here where I live, we’ve had several car/train accidents where people were badly injured or killed, and that’s why the lighted crossings were put in place of the old type posts and signs. Tracklayer
The DOT usually determines what crossing protection is needed and is responsible for the cost of installation. The railroad in then responsible for the cost of maintaince.