In 1912 the first work began for the construction of a separate pair of tracks for urban traffic from Gdańsk Główny towards Sopot. The work interrupted by the outbreak of World War I. This line was completed between Gdańsk and Sopot Wyścigi in 1925. After World War II, in 1950, it was decided to continue work on the separation of suburban traffic. In 1952 SKM arrived in Sopot and a year later, on 22 July 1953 it was extended to Gdynia (one track). On 1 May 1954 the second track was opened.