Train operator First Great Western (FGW) published thousands of leaflets which showed a service in Cornwall that does not exist.
The leaflet was intended to highlight cheap fares
The map showed a phantom direct line between Falmouth and Redruth as part of a cheap fares promotion.
FGW has apologised to customers and blamed a production error, saying there was no intention to offer misleading service information.
A correct version of its routes has now appeared on the FGW website.
Julian Crowe from FGW said the artwork had misaligned a station on the Falmouth line, so that Truro appeared as Redruth.
He said: "It's one of those easy mistakes. The artwork was drawn incorrectly.
"The people who checked it failed to spot it and all of a sudden it's in thousands of households across the county.
"Very embarrassing really, but these things happen."
He said it was not meant to be a route map and was not to scale.
"The message behind it was about cheap fares and if this has drawn attention to the good value fares we have got out there this summer, then worse things have happened."