In an action against the secretary, a judgment against him shall not be granted unless the court in which the action is brought is satisfied that all reasonable efforts have been made by the parties, other than the secretary, to ascertain the identity of the motor vehicle and of the owner and driver thereof, and that:

  (a) In the case of actions under section 12, the identity of the motor vehicle and of the owner and driver thereof cannot be established; or

  (b) In the case of actions under section 15, the identity of the driver of the motor vehicle that caused the death or injury or property damage cannot be established.