In 1990, the
Ministry of Transport commissioned a study regarding the construction of a new line connecting
Helsinki with eastern Finland, prompted by the capacity problems of the
Helsinki–Riihimäki railway. Three main routes for the new connection were proposed:
Helsinki–
Lahti–
Mikkeli, Helsinki–
Kouvola, and Helsinki–
Kotka–
Hamina–
Luumäki. All three options were deemed superior to the alternative of simply upgrading the existing lines. The Kotka option was found to be the least economically viable of the three, while those of Lahti and Kouvola were found to be about equal in this respect. The study was completed in 1992, favoring the Lahti option. The construction of the Kerava–Lahti railway line took four years and cost €331 million. At the time it was the first new passenger railway to be opened in Finland since completion of the
Jämsänkoski–
Jyväskylä line in 1977, reducing the journey time between Kerava and Lahti by 26 kilometres. Funding was provided by the Finnish government and the
European Union, with the route forming part of the EU's "Nordic Triangle" TEN-T strategic transport route. ==Services==