How and Why Freight Trains Deviate From the Timetable: Evidence From Sweden

European infrastructure managers (IMs) create annual timetables for trains that will run during a year. Freight trains in Sweden often deviate from this by being
added
,
canceled
,
delayed
or
early
, resulting in increased costs for IMs and railway undertakings (RUs). We investigate the frequency of and causes for these deviations, using one year of operational data for 48,000 trains, and 15 stakeholder interviews. We find that about 20% of freight trains are
added
once the timetable has been created, and that
cancelations
occur for about 35% of freight trains, mostly at the RUs’ initiative.
Delays
are common: some 40% of departures, 30% of runtimes, and 20% of dwell times are delayed. Running
early
is even more common: 80% are ready to depart early, and 60% do so, while 40% of runtimes and 75% of dwell times are shorter than scheduled. We find links and feedback loops between the root causes for these deviations and suggest that IMs reserve more of the capacity that is needed for freight trains and instead distribute it throughout the year. This could lead to more appropriate, attractive, and reliable timetables for freight trains, whilst greatly reducing the amount of planning effort.