Trans-Siberian Railroad, rail line, linking European Russia with the Pacific coast. Its construction began in 1891, on the initiative of Count S. Y. Witte, and was completed in 1905. The completion of the railroad greatly affected the history of the Russian Empire, the Soviet Union, and modern Russia by opening up Siberia to development.

The original line began at Chelyabinsk and ran generally east through Omsk, Novosibirsk, Krasnoyarsk, Irkutsk, and Chita; it traversed Manchuria and reentered Russian territory before ending at Vladivostok. The Manchurian section of the line is known as the Chinese Eastern RR. The present Trans-Siberian RR branches off from the original line at Chita to follow, roughly, the Amur and Ussuri rivers and reaches Vladivostok by way of Khabarovsk; it lies entirely in Russian territory. The Moscow-Vladivostok run is 5,785 mi (9,310 km); the electrification of the entire line was only completed in 2002. The line carries both freight and passengers.

The Trans-Siberian RR now has several branch lines, notably the line connecting Omsk with Yekaterinburg. A branch to Ust-Kut connects with the Baykal-Amur Mainline (BAM). The railroad is also linked with the Turkistan-Siberia RR.

Baykal-Amur Mainline (BAM), railroad line linking central Siberian Russia with the Pacific. The BAM parallels the Trans-Siberian RR but passes north rather than south of Lake Baykal. It is 1,928 mi (3,102 km) long, with 1,987 bridges. Its eastern terminus is Sovetskaya Gavan on the Tatar Strait. It was begun in 1938 but was dismantled for parts after World War II. It was restarted in 1974 and officially completed in 1991. Although it operates along its entire length, it is little used, largely because of a lack of funds to maintain it.