(a) The State's Highway Safety Plan for a fiscal year and the State's authority to incur costs under that HSP shall expire on the last day of the fiscal year.

(b) Except as provided in paragraph (c) of this section, each State shall submit a final voucher which satisfies the requirements of § 1300.33(b) within 90 days after the expiration of the HSP. The final voucher constitutes the final financial reconciliation for each fiscal year.

(c) The Regional Administrator may extend the time period for no more than 30 days to submit a final voucher only in extraordinary circumstances. States shall submit a written request for an extension describing the extraordinary circumstances that necessitate an extension. The approval of any such request for extension shall be in writing, shall specify the new deadline for submitting the final voucher, and shall be signed by the Regional Administrator.