49 CFR § 238.702
Definitions
November 18, 2020
As used in this subpart—
Cab means a compartment or space within a trainset that is designed to be occupied by an engineer and contain an operating console for exercising control over the trainset.
Integrated trainset means a passenger train in which all units of the trainset are designed to operate together to achieve the trainset's structural crashworthiness performance.