The Trans–Siberian RailwayThe Trans–Siberian Railway (TSR) is a railway network that connects Western Russia and Russia's Far East. With a length of almost 9,289 kilometres (5,772 miles), it is the world's longest railway line, stretching from Moscow, Europe's largest city, to Vladivostok, on the Pacific Ocean.
Why are trains allowed to be so long?
Fuel EfficiencyBecause GHG emissions are directly related to fuel consumption, longer trains mean reduced GHG emissions. That's why capping train length is not environmentally sound.