Rail transport
Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. The oldest, man-hauled railways date to the 6th century B.C.; the method grew more popular after the introduction of steam locomotives in the 19th century. Here we can see four BNSF GE C44-9W diesel locomotives hauling a mixed freight train along the Columbia River in the US.Photograph: David Gubler