What is headway in rail operations?

• A. The time interval between successive trains, typically at a given location
• B. The movement of trains or equipment without passengers
• C. The time it takes for a train to travel from its origin to its destination
• D. The official schedule listing departure and arrival times

Answer: (A)

Headway is the time gap between trains as they pass a fixed point on the track. This spacing determines how many trains can run per hour in one direction, because smaller gaps let more trains fit into a given time, within the limits of signaling, braking distance, and track layout. For example, a two-minute headway means about 30 trains per hour per direction, assuming the system can safely support that cadence. Headway is a key measure used in planning and operations to balance safety with throughput: shorter headways increase capacity but demand tighter control and quicker braking, while longer headways reduce capacity but improve reliability and safety margins. This concept is distinct from the total journey time from origin to destination, the movement of trains without passengers, or the timetable listing departure and arrival times.