How fast is the northern line?

The Northern Line of the London Underground typically operates at speeds of up to 60 mph (97 km/h) in sections where it is not constrained by stops or curves. However, average speeds during service are lower due to frequent stops and congestion, usually around 20-30 mph (32-48 km/h). The line’s speed can vary depending on factors such as the time of day and train schedules.