It is thought that European land trains developed from the lightweight narrow gauge trains built by Decauville and the like between the wars. When the little steam engines were replaced with petrol or diesel locos they were often given fake chimneys to look like steam trains. When the diesels also wore out, various French railways began to pull their railway coaches with farm tractors which were wide enough to straddle the narrow tracks. These tractors were also modified to look like steam locos. It was a small step to abandon the rails altogether and build equivalent road coaches to emulate their Decauville ancestors.
Evolution images below.
Decauville train at Royan
Steam-outline diesel at Cap Ferret
Steam-outline farm tractor running
astride the rails and pulling
Decauville railway coaches at Saint-Ambroix
Primitive steam-outline farm tractor running on the road at Fort-Mahon