What does the score mean?
The score is made up of four elements - the cumulative late running of trains, the number of minor signalling errors per hour, plus the total of other more significant signalling errors. The score is updated frequently and the break-down into the four components is shown in a context-sensitive help message.
The score will reduce as significant signalling errors are made, it will rise or fall as the 'average lateness' of trains gets better or worse and it will rise or fall as the number of minor errors per hour improves or deteriorates.