Witches trains, also known as zombie trains, are an element of the folklore of Southern Africa. As the story goes, a person wandering alone at night may encounter a train, sometimes on an established track, sometimes simply moving along the landscape as if on a track despite the lack of rails, that will stop for them. If the unlucky wanderer boards the train, a conductor will ask whether they are seeking a "single" trip (one way) or a return trip.
Answering "single" results in the unlucky passenger being killed and resurrected as a zombie, to spend their un-life doing the bidding of a witch or sorcerer. Those who respond "return" will find themselves beaten, and then thrown from the train several miles away from where they boarded, often stranded with no clear means to return home.
Commentary: It needs to be made clear - the Zombie of African and Caribbean folklore is a different creature from the zombie of U.S. and European pop culture.
In African and Caribbean folklore, the zombie may be someone who has actually died and been re-animated by a sorcerer or priest, or they may be someone who has never actually died but been made to look dead, and then had their soul captured by the sorcerer or priest. Either way, the body is alive again, but without a mind or will of its own, and can be made to do the bidding of its master. There are numerous accounts of former zombies being released, or otherwise re-gaining their minds/souls/wills, and leaving their masters. And there is active debate as to just how much truth there may be to claims of pharmacological zombies - people put into a zombie state through the use of herbs or chemicals and used as slave labor by the people who prepared the concoctions. A discussion of how much, if any, truth there is to these often sensationalized accounts is beyond the scope of this blog. I would recommend that anyone interested start by reading materials available through groups such as National Geographic, and beware the frequent news accounts, which tend to dwell on the creepy or gruesome without critically examining the claims made.
The story of the zombie train appears to be tied into the concurrent development of railroads and European colonization. Local folklore mixed with political realities in which the European colonists were oppressing the locals in a matter somewhat reminiscent of how a sorcerer oppresses his zombie slaves. In post-colonial times, this story appears to have become attached to the development and enforcement of apartheid laws in South Africa, where a white minority held both de-facto and legal control over the lives and well beings of a large but subjugated black majority. Moreover, both during the apartheid era, and following it, cheap workers from other locations were often brought in to work sites by train rather than hiring local workers, leading to further impoverishment of local communities, the exploitation of migrants, and a distrust of outsidersm, making the zombie train a fearful thing both for migrants who fear becoming zombies, and for those who are displaced in the workforce by migrants, who they perceive as zombie-like.
In a sense, this appears to be a case where political realities came to be reflected in the folklore. An interesting, if disturbing, development.
Sources: Wikipedia, Blog