A conductor is operating in a territory where the timetable shows a maximum speed of 40 mph for freight trains and a special instruction reduces speed to 25 mph for the next 5 miles due to track work. Which speed limit applies?

1. 40 mph, as the timetable is the governing document
2. 25 mph as shown in the special instruction, which supersedes the timetable for that section
3. The average of 40 and 25, or approximately 32 mph
4. 30 mph, as a general safety margin should be applied to any temporary restriction