Swedish Transport Administration
Maintained by the Swedish Transport Administration, the Western Main Line is electrified and consists entirely of double track, except the four-track sections between Gothenburg Central Station and Olskroken (), in Järna (), and south of Stockholm, between Flemingsberg and Stockholm South Station, about . The last section between Stockholm South Station and Stockholm Central Station runs mainly on a two track bridge. Before the Stockholm City Line was opened in 2017, the bridge was a serious bottleneck, as all trains had to use the same tracks.