It depends on the standard of the local rail network as well,  Our local railway route lost its ability to run class 43's in about 1993, runing direct to Birmingham at reasonably high speed. One of the main reasons that it was reported to have happened was so that the train companies could reduce the ammount spent on track maintenance by running lighter trains. one of the side effects of this are frequent patches where we are told that we are running slowly in an area due to track conditions.

Any idiot can face a crisis - it's day to day living that wears you out.