Railroad crossings can be very dangerous for bicyclists. For some reason, people decide to place these crossings on curved roads, which causes the bicyclist to fall quite hard. If the track was perpendicular to the wheel, there would be no issue. The problem arises specifically due to the fact that there is a turn involved while crossing the tracks.

When you turn your bicycle going over a railroad track, the wheel can easily get stuck. Your momentum keeps carrying you forward, but the bicycle doesn't want to go anywhere. In the video down below, you can see exactly what I'm talking about. It's extremely dangerous and there were many people that almost got hit by cars because of the tracks proximity with the lanes.