41 CFR § 102-5.65
What procedures apply when the need for home-to-work transportation exceeds the initial period?
June 9, 2020
The agency head may approve unlimited subsequent determinations, when the need for home-to-work transportation exceeds the initial period, for no longer than:
(a) Two years each for field work, updated as necessary; and
(b) Ninety calendar days each for other circumstances.