Guides and notes
How to read a timetable, what the delay figures on this site mean, and how they are measured. Written from the archive, and short on anything we cannot show you.
Why a train can be late at one station and on time at the next
Delay is not a single property of a train. It is a measurement taken at a place, and it changes along the route. Understanding that is the difference between reading a punctuality figure correctly and being misled by one.
Why we publish a median delay, not an average
An average delay is dragged upward by a handful of very bad days, so it describes a journey most passengers never take. The median describes the ordinary one. Here is the difference, and why it matters when you are deciding what time to leave for the station.
What we mean when we say a train was on time
Every punctuality figure hides a set of choices: how late counts as late, how many runs are enough to publish, which arrival the number describes, and what gets thrown away. Here are ours, in full, so you can judge our numbers rather than trust them.