In a text I'm translating, I've come across the concept of a market train. To my misinformed understanding, market trains might be those trains that carry crates and boxes for commercial purposes, but this doesn't seem to be the case (despite the train having a freight engine).
Rather, the carriages (we're talking a WW2 era train here) are meant to transport a large number of people from the main town to a satellite town which is called a "market destination" - a place where everybody in town has an aunt or a cousin.
What does "market" mean in this context? How else can I call this kind of train?
The text comes from an obscure roleplaying game manual published this century and inspired by a book by Alan Furst called The Polish Officer. The game is set in Poland around the day when the Germans invaded Warsaw.
I see in comments about market-day trains and to be true there's this passage in the manual:
They are market coaches for carrying people out of the city on Sundays and holidays
[It] will look like an innocent market train, the sort that putters between cities on week-ends making every stop on the line.