An automated speed control system for a locomotive having a tractive effort mechanism for moving the locomotive along a track and a braking mechanism for reducing the locomotive's speed along the track. The system including a locomotive controller that includes a memory to store computer-executable instructions, and a processor in communication with the memory to execute the instructions to retrieve one or more track grade maps each indicative of a grade of at least a portion of the track along which the locomotive is travelling, retrieve train makeup, obtain a maximum distance to a specified stopping point of the locomotive along the track, and dynamically calculate a speed limit for movement of the locomotive along the track, according to the retrieved track grade map, retrieved train makeup data, and obtained maximum distance to the specified stopping point.