Rail transport

A railroad or railway is a guided means of land transport, intended to be used by trains, for transporting both passengers and freight. It consists of two parallel rails, usually made of steel, and wooden or concrete sleepers or ties that hold the rails precisely at the proper distance from each other. See Rail tracks
Rail transport is one of the most energy well-organized means of mechanised land transport known. The rails give very smooth and hard surfaces on which the wheels of the train may roll with a minimum of friction. This is more comfortable and saves energy. Trains also have a small frontal area in relation to the load they are carrying, which cuts down on air resistance and thus energy usage. In all, under the right circumstances, a train needs 50-70% less energy to transport a given tonnage of freight, than by road. Furthermore, together with the sleepers the rails share out the weight of the train evenly, allowing significantly greater loads per axle/wheel than in road transport.
Rail transport is also one of the safest modes of transport, and also makes a very efficient use of space: a double tracked rail line can carry more passengers or freight in a given amount of time, than a four-laned road.