You are operating on a single light engine with no cars on the main line. What speed is not to be exceeded?

You are operating on a single light engine with no cars on the main line. What speed is not to be exceeded?

• A. 40 mph
• B. 25 mph
• C. 20 mph
• D. 30 mph

Answer: (D)

When you’re moving a single light locomotive on the main line, you’re restricted to a speed that allows safe stopping and reliable signal observation without the help of the extra mass and braking that cars provide. In CSX rules, that not-to-exceed speed is 30 mph, so you must not exceed it. This speed is chosen because it balances safe stopping distance with realistic main-line operation for a lone engine. Going faster would impair your ability to stop for signals, switches, or an unexpected obstruction. The other numbers are for different operating contexts: 40 mph would be too fast for this setup, while 25 mph and 20 mph are typically used for yard work or restricted-speed operations, not for a lone engine on the main line.

When you’re moving a single light locomotive on the main line, you’re restricted to a speed that allows safe stopping and reliable signal observation without the help of the extra mass and braking that cars provide. In CSX rules, that not-to-exceed speed is 30 mph, so you must not exceed it.

This speed is chosen because it balances safe stopping distance with realistic main-line operation for a lone engine. Going faster would impair your ability to stop for signals, switches, or an unexpected obstruction. The other numbers are for different operating contexts: 40 mph would be too fast for this setup, while 25 mph and 20 mph are typically used for yard work or restricted-speed operations, not for a lone engine on the main line.