These type of trains are built using lightweighting techniques, with the purpose of reducing operating costs.
[3][4] Most light trains in use in the 21st century were developed for mainline rail roads in Europe, however they do not meet the crash-safety guidelines from the U.S. Federal Railroad Administration (FRA).
[6] Early examples where the 1931 U.S. Bullet and the 1932 German prototype Flying Hamburger, following a production series later named VT 04.
In France, the TELLi project aims to introduce light trains starting in 2029.
[7] Though light trains are used on mainline rail roads in Europe, in the Americas they are mostly used on isolated tracks: