49 CFR §236.567

1. (a)Except as provided in subparts H or I of this part, where an automatic train stop, train control, or cab signal device fails and/or is cut out en route, the train on which the device is inoperative may proceed to the next available point of communication where report must be made to a designated officer, at speeds not to exceed the following:
   1. (1)If no block signal system is in operation, restricted speed; or
   2. (2)If a block signal system is in operation, according to signal indication but not to exceed 40 miles per hour.
2. (b)Upon completion and communication of the report required by paragraph (a) of this section, a train may continue to a point where an absolute block can be established in advance of the train at speeds not to exceed the following:
   1. (1)If no block signal system is in operation, restricted speed; or
   2. (2)If a block signal system is in operation, according to signal indication but not to exceed 40 miles per hour.
3. (c)Upon reaching the location where an absolute block has been established in advance of the train, as referenced in paragraph (b) of this section, the train may proceed at speeds not to exceed the following:
   1. (1)If no block signal system is in operation and the train is a passenger train, 59 miles per hour;
   2. (2)If no block signal system is in operation and the train is a freight train, 49 miles per hour; and
   3. (3)If a block signal system is in operation, 79 miles per hour.