Train from Reims to Caen

RailEurope is rather notorious for not showing all options. It sometimes seems to prefer to sell the more expensive tickets, but perhaps there is a different explanation (I'm trying to be kind here).

When traveling between regional cities in France you do frequently have to go through Paris; it happened to me three times this summer, even when both origin and destination were on the same side of Paris. When you have to change train stations in the big city, it is nail-biting time even when the first train is on schedule. At least in your case Paris is more or less directly in between your starting and ending points.

Looking at the 9:08 AM departure, I see that the Paris transfer (Auber to St.-Lazare) is by walking, so the two stations must be very close together. You wouldn't have to fool with the Metro to make that shift. On the other hand, you'd have a total of three changes to make, and in my recent experience it's not uncommon for French trains to be 10 minutes or more late. In one case I arrived in Paris only to be told that my connecting trains wasn't going to run at all that day. This is likely to be the most costly alternative (I haven't checked SNCF.com to be sure).

The 9:49 AM departure has a 9-minute transfer in Epernay (nervous-making) but nearly 3 hours for the cross-town transfer in Paris, so you should even have time to find a place for some sort of sit-down lunch near St-Lazare. If you can stomach that 9-minute initial transfer. The trip as a whole is very long, of course.

The 11:10 AM departure also takes much longer than the first option (it's all regional trains) but the shortest transfer time is 18 minutes and you don't have to go through Paris at all. And it will probably be the cheapest since it involves no fast trains.

Honestly, I don't know what I'd do in your shoes. I'd probably opt for the first departure, which has the virtue of being the fastest and getting you started the earliest, so if something does go wrong you have some recovery time.

Or I'd change my itinerary to avoid the whole problem. Are you also planning to see Epernay? If you stayed there instead of in Reims, you'd avoid the first transfer on the second departure, eliminating some risk. Unfortunately, you'd still have a trip lasting over 6 hours.

The train line between Paris and Caen has been under construction on weekends for a long time now. It keeps recurring that people see scary Sunday detours on that route when researching in advance. They may or may not be the final plan, depending on how construction progresses. Frankly, if you could travel on a Monday, you'd save yourself a lot of worry between now and then.

And yes, if connecting in Paris, one often must change stations by other means of transport. The several stations that ring the city center all serve different directions of travel, with no above-ground trains crossing through the middle. London is similar.

Deutche Bahn is handy for schedules, sometimes precisely because it doesn't sell tickets to most places. Therefore, it happens to reflect RER and Metro connections in Paris, which most rail sites don't, and will reflect schedules that have been published but not opened for sale.

Many train sites do focus on the fastest train schedule solutions, avoiding slower options unless you request them, or unless there are not many faster ones. That's not unique to Rail Europe. But remembering again that they are a shopping cart and not a complete timetable, not all legs of a trip (e.g. faster vs regional) go on sale at the same time. Nor can the cart's little brain piece together more than a couple of connections on one ticket. It helps to break down a ticket search into smaller chunks.

The usual route from Reims to Caen by train would be from Reims to Gare de l'Est in Paris, and from Gare Saint-Lazare to Caen. I don't know why any site would recommend you to use Auber station in Paris - the best way to get between those two major stations is to get the RER Line E from Magenta station (signposted from Est, a short walk) to Saint-Lazare. One stop and you can do it with a normal Paris transport single ticket.

I got the routing from the Deutsche Bahn website. I had never heard of that station myself.

Most connection shown on the DB site are via Est and St. Lazare. Auber comes in as an alternative some times when a few minutes are saved - at the expense of four transfers.

We so appreciate all of your comments and suggestions, especially taking the time to look at the train schedules.
We are going to re-think going from Reims right to Caen. If we go right to Paris from CDG, then to Caen we can get non-stop train. It would leave our trip to Reims as a day trip, but that sounds like a better option right now.
Thank you for all your help!