That results in very little friction created when compared to an automobile with rubber tires on asphalt or concrete. The fastest method is to call the local police or 911. Tell them the location, generally the name of the road intersecting the tracks or the nearest town, and they will contact the railroad. The railroad dispatcher can reach the locomotive engineers by radio and they will do everything possible to get any approaching trains stopped in time. Don't try to flag down the train.
Most engineers can effectively see about a half-mile ahead of their train.
There's not enough time to stop by the time they see you flagging them down. Reflectors on rail cars quickly become ineffective because of dirt picked up by the rail cars when they're moving. Compliance and maintenance would be impractical because of the variations in sizes and shapes of rail cars combined with the fact that there are numerous owners of this equipment. People also drive into the sides of trains in broad daylight. Actually, about two-thirds of all collisions at crossings in the United States happen in the daylight hours.