Rail gauge in Estonia
Estonia mainly uses a track gauge of 1,520 mm (4 ft 11 27⁄32 in) or 1,524 mm (5 ft), inherited from the Russian Empire times.
Estonia converted relatively late from the Soviet Unions redefinition of the gauge from 1,524 mm (5 ft) to 1,520 mm (4 ft 11 27⁄32 in).
Since post-independence all renovated tracks owned by Eesti Raudtee have gauge 1,524 mm. Other tracks have gauge 1,520 mm.
There has been a proposal from the EU to build a standard gauge railway from Tallinn to Warsaw, the Rail Baltica. For cost reasons the current plans only see an upgrade of the existing Russian gauge railway to Lithuania over Riga, a new railway through Lithuania, and upgrade through Poland. It will have standard gauge only south of Kaunas, Lithuania, not in Estonia.
Historically Estonia had 750 mm (2 ft 5 1⁄2 in) narrow-gauge installations.
Tallinn has tram with 3 ft 6 in (1,067 mm) gauge.
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Wikipedia