Which term describes a block signaling approach where the use of each block is governed by manual controls, block-limit signals, or both, based on information received by telephone or radio?

• A. Automatic Block Signal System
• B. Manual Block Signal System
• C. Block Signal System
• D. Track Car

Answer: (B)

This question focuses on how block occupancy is authorized when human communication governs train movements. In a Manual Block Signal System, each block’s use is controlled by manual actions—dispatchers or station operators—who authorize entry based on information received by telephone or radio, and by block-limit signals that indicate when a block is occupied or not.

This differs from automatic systems, where track circuits detect a train’s presence and signals change automatically without direct human authorization for each block. The term described here specifically highlights the reliance on human control and communication to manage block occupancy, which is why it’s the best fit.