Amtrak's Viewliners are maybe the last modern passenger car with fluting. Is fluting even necessary anymore? Is it only an aesthetic consideration? Would Amtrak order new Siemen's Venture coaches with fluting to match the Viewliners? Just curious if anyone has any ideas on this.
Fluting does contributes to the overall strength of the outer wall, but I doubt they'd add it after passing the crush tests.
UP operated a mix of smooth and fluted cars which wasn't too distracting. I think they still have at least one in the business car fleet (UPP 202 Willie James which started out as Pacific Domain).