Beyond bi-mode diesel-electric options, several technologies offer zero tailpipe emissions on non-electrified tracks and the industry seems set to move towards these in the coming decades. The most innovative of such technologies are battery electric trains and hydrogen fuel cell trains. Battery electric trains with smaller batteries can also be used on partially electrified lines, enabling electrification costs to be sharply reduced by missing out those portions of track that are most difficult to electrify (such as bridges or tunnels).

Under optimistic assumptions about fuel cell cost reductions, hydrogen trains could become competitive against other passenger services options with low frequency of utilisation. Hydrogen fuel cell technology is most competitive for services requiring longdistance movement of large trains with low-frequency network utilisation, a common set of conditions in rail freight. The use of hydrogen in rail could be combined with its use for forklifts, trucks and other railyard and logistics hub machinery to decrease costs and improve flexibility.