On 315 the tires are well within FRA standards and spects. They were not turned during restoration, and other then what little ware they have received in the ten years since restoration, they are the same as when she retired from active service. I don't know about the rough riding over the switches, as this is the only condition we've ever experienced on her. I have been told, by an Ol' Timer, ( don't know if its true or not) that a set of blind drivers with a little ware on them tracks better then fresh turned (new) ones, especially in reverse on a 2-8-0.