Since the train's speed can be such a critical factor in a grade crossing accident, it would seem the question of who determines the speeds at which railroads operate their trains over grade crossings would be very important in determining liability when a crossing accident occurs. However, because of the supremacy of federal law (and accompanying regulations), this is generally not the case.
Operating under the authority granted it by Congress, the Federal Railroad Administration has issued regulations that establish different classifications of track with a maximum speed set for each track classification. As long as a railroad maintains its track to meet the criteria for each track classification it is operating on, it need only comply with the required maximum speed. The practical effect of this is that as long as a train involved in a grade crossing accident was being operated at or under the federally established speed for that track when the accident occurred, it is extremely difficult, if not impossible, to make a claim that the railroad was negligent for operating at an excessive rate of speed.