Capacity of the railway network

Railway infrastructure capacity depicts the railway route train traffic capacity per unit of time based on the railway network characteristics. Railway infrastructure capacity is a relative concept that cannot be assigned an unambiguous value; instead, it depends on infrastructure like the number of tracks; speed limits and gears; equipment features, such as braking distances; and timetables, such as drive, stop and turning times; allowances and train intervals.

Traffic control can be used to impact capacity. Axle loads and train lengths are also connected to capacity. Both can influence the number of trains.

In practice, the capacity status on the railway network varies from day to day depending on the number of trains in operation. The time of day of the peak hour also varies from section of track to another. When examining railway infrastructure capacity, time required by maintenance work on the tracks must also be factored in. A defective capacity will first manifest in delayed trains, but may lead to an inability to implement plnned train services.

Even after the current projects have been completed, major challenges remain on the same tracks. Many of these tracks are located in the TEN-T core network. The arterial route experiences capacity issues on the entire Helsinki–Tampere line and on the Ylivieska–Oulu line further north. In addition to insufficient capacity on the Espoo City Rail Link, the Coastal Railway suffers from frequent disturbances. There are challenges on the Luumäki–Vainikkala line and challenges will remain on the Luumäki–Imatra line. The goods transport connections between Kontiomäki, Oulu and Ylivieska and Kontiomäki, Iisalmi and Ylivieska provide alternative routes to each other. By further developing the Kontiomäki-Oulu stretch, the burden on the route running through Iisalmi can be alleviated. The most significant capacity issues on the Tampere–Jyväskylä line are on the single-track Orivesi–Jyväskylä section. Various challenges with combining passenger traffic and goods transport have also been found on other routes, especially between regional centres. 

Traffic volumes developing in the manner estimated and causing increasing needs will affect the same sections of track that are currently identified as needing development. The issues posed by larger challenges have wide-reaching affects: the situation on the Helsinki–Kerava route, for example, affects the development options in east-bound traffic, and the situation on the Helsinki–Tampere route affects the development options of traffic from Tampere to other directions. 

Goods transports in particular are prone to sudden changes in transport flows or transport destinations. The changes affect the operation of the railway network. They may cause the need to ensure network reliability and development, but they may also reduce traffic on some sections of the railway network. Passenger traffic may also experience changes that do not line up with forecasts, and already has to some degree. Passenger traffic on some sections increased more than expected before the COVID-19 pandemic, for example. During the pandemic, railway passenger volumes have decreased dramatically, but the number of train services has remained more or less the same.

In relation to the current status and basic forecasts, core development needs related to improving capacity (also with regard to minor travel time reductions) would cost 1–1.5 billion euros (this does not include the larger investments on the Helsinki–Tampere and Helsinki–Turku routes or the East Rail (project companies)).