49 C.F.R. § 397.209 – Preemption processing.

(a) The Administrator may initiate an investigation of any statement in an application and utilize in his or her evaluation any relevant facts obtained by that investigation. The Administrator may solicit and accept submissions from third persons relevant to an application and will provide the applicant an opportunity to respond to all third person submissions. In evaluating an application, the Administrator may consider any other source of information. The Administrator may convene a hearing or conference, if a hearing or conference will advance the evaluation of the application.
(b) The Administrator may dismiss the application without prejudice if:
1. (1) he or she determines that there is insufficient information upon which to base a determination; or
2. (2) he or she requests additional information from the applicant and it is not submitted.