Re: FRA track class standards

This is out of the 49 Code of Federal Regulations(CFR) 213.9. Remember, this part applies to all standard gage track in the general railroad system of transportation.
Classes of track: operating speed limits.
213.9(a)
the following maximum allowable operating speeds apply -
[In miles per hour]
------------------------------------------------------------------------
The maximum
Over track that meets all of the allowable
requirements prescribed in this operating speed operating speed
part for-- for freight for passenger
trains is-- trains is--
------------------------------------------------------------------------
Excepted track.................... 10 N/A
Class 1 track..................... 10 15
Class 2 track..................... 25 30
Class 3 track..................... 40 60
Class 4 track..................... 60 80
Class 5 track..................... 80 90
------------------------------------------------------------------------
213.9(b)
(b) If a segment of track does not meet all of the requirements for its intended class, it is reclassified to the next lowest class of track for which it does meet all of the requirements of this part. However, if the segment of track does not at least meet the requirements for Class 1 track, operations may continue at Class 1 speeds for a period of not more than 30 days without bringing the track into compliance, under the authority of a person designated under § 213.7(a), who has at least one year of supervisory experience in railroad track maintenance, after that person determines that operations may safely continue and subject to any limiting conditions specified by such person.