I am on the Loire to South of France tour which starts September 18 and have a TER ticket from Montparnasse to Chartres. I have a healthy (or unhealthy) fear of French train stations. It looks like most TER trains run from platforms/tracks 25-28 located in Hall 3, a separate station connected to the main station. However, a TER train could possibly be on a platform/track in the main concourse (Hall 1). Since it could take up to 20 minutes to walk from the main concourse (Hall 1) to Hall 3, I wanted to see what other experiences travelors have had and what advice you have.
Thanks