Train Headway Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 28, 2026Train Headway Calculator
Planning line capacity on a railway? This calculator estimates the minimum safe time interval between successive trains on the same track.
Total Separation = Train Length + Braking Distance + Safety Margin
Minimum Headway = Total Separation / Speed(m/s)
Example
A 200m train, 800m braking distance, 80 km/h speed, 500m safety margin:
Total Separation = 1,500 m → ~1.1 minutes minimum headway
Why Headway Directly Determines Line Capacity
Headway is the minimum safe time interval required between trains on the same track section - shorter headway allows more trains per hour on the same infrastructure, making it one of the single biggest levers for increasing a rail line's passenger or freight throughput.
Modern Signaling Can Reduce Required Headway
Modern signaling systems, like moving-block or cab signaling that continuously track exact train position, can safely reduce required headway compared to older fixed-block systems that reserve entire track sections regardless of a train's actual position within them - directly increasing achievable capacity.