21. When an accident has occurred resulting in a temporary suspension of traffic, and either the original line and works have been rapidly restored to their original standard, or a temporary diversion has been laid for the purpose of restoring communication, the original line and works so restored, or the temporary diversion, as the case may be, may, in the absence of the Inspector, be opened for the public carriage of passengers, subject to the following conditions, namely:- (a) that the railway servant in charge of the works undertaken by reason of the accident has certified in writing that the opening of the restored line and works, or of the temporary diversion, will not in his opinion be attended with danger to the public using the line and works of the diversion; and (b) that notice by telegraph of the opening of the line and works or the diversion shall be sent, as soon as may be, to the Inspector appointed for the railway.