Trains are roughly 3m wide, so 1m segments would be good. In other words, a sleeper car would have 1m hallway, 2m of cabins. Most cars have the 1m section going through the center. Overlap into the center aisle is fine to some degree, since it's not a full meter of aisle usually.
Dining and lounge cars will be fun. Seating and baggage cars should be easy.
Aisle width seems to be from 24" (2m) to 32". Seat width about 19".
*** NOTES https://railwaywondersoftheworld.com/great_northern.html https://www.bluebell-railway.co.uk/bluebell/car_fs1.html https://sketchfab.com/3d-models/deluxe-victorian-railway-carriage-932e17966eae4234b1b61c2b6d093ec2 https://sketchfab.com/3d-models/interior-design-train-scene-ad61f948205647a2a1a59bd944989abc https://sketchfab.com/3d-models/1890s-train-car-d129961e10a146928222022cee5db1c1 https://turniprail.blogspot.com/2011/11/passengers-praise-and-poetry-britains.html https://web.archive.org/web/20210203040753/https://nationalrrmuseum.org/blog/tidbits-from-the-dining-car/ https://preview.drivethrurpg.com/en/product/151326/1880s-Train-Car-Map-Set (assume 3m wide) https://www.pinterest.com/pin/497788565062301279/
Trains are roughly 3m wide, so 1m segments would be good. In other words, a sleeper car would have 1m hallway, 2m of cabins. Most cars have the 1m section going through the center. Overlap into the center aisle is fine to some degree, since it's not a full meter of aisle usually. Dining and lounge cars will be fun. Seating and baggage cars should be easy.
Aisle width seems to be from 24" (2m) to 32". Seat width about 19".