What is the maximum allowable speed for restricted speed?

The maximum allowable speed for restricted speed is indeed 20 mph. Restricted speed is defined as a slow speed that allows for stopping within half the range of visibility. It is designed to ensure safety in areas where one might encounter unexpected conditions, such as obstructions or other trains.

In practice, when a train is operating at restricted speed, it is critical that the crew remains vigilant and prepared to respond to any situation, which emphasizes the importance of limiting speed to a manageable level. While 10 mph, 12 mph, and 15 mph can all be cited in various contexts or situations, the stipulations surrounding restricted speed typically define the upper limit as 20 mph to ensure a balance between operation efficiency and safety precautions. This speed allows the crew to maintain control while remaining responsive to information that may necessitate quick action.