wheel flat limits for passenger cars

My wife and I had a sleeper (Renaissance) on the VIA to Halifax a few months back. Coming back was OK but going we had a flat on the wheels under our berth. As I lay there I just longed for the curves and silence as we ran on a good bit of the tread. No, the noise wasn’t soothing like the old jointed clickety-clack.

Q. How do the acceptable limits for passenger cars compare with the other person-carrier, ie locomotive?

Thank you.

Flat spot discussion on another forum

http://www.railroad.net/forums/viewtopic.php?f=69&t=89299