(a) Whenever a party has the right or obligation to take action within a period prescribed by this part, by a notice given thereunder, or by an order or regulation, the DOT decisionmaker or the administrative law judge assigned to the proceeding, as appropriate, may:

(1) Before the expiration of the prescribed period, with or without notice, extend such period, or

(2) Upon motion, permit the act to be done after the expiration of the specified period, where good cause for the failure to act on time is clearly shown.

(b) Except where an administrative law judge has been assigned to a proceeding, requests for continuance or extensions of time, as described in paragraph (a) of this section, shall be directed to the DOT decisionmaker. Requests for continuances and extensions of time may be directed to the Chief Administrative Law Judge in the absence of the administrative law judge assigned to the proceeding.