Depends on the country. Most of the UK away from London and apart from a handful of main lines is diesel. Elsewhere in Europe, most rural lines still are. It's

Depends on the country. Most of the UK away from London and apart from a handful of main lines is diesel. Elsewhere in Europe, most rural lines still are. It's likely many of these will switch to either hydrogen or battery trains, the latter possibly with shorter stretches of overhead wire to recharge.