Cal. Pub. Util. Code § 99408

Any action to review, set aside, void, or annul the decision of a transportation planning agency made pursuant to Section 99401.5 shall be filed within 30 days after the agency makes its decision, or after the secretary has reviewed the decision pursuant to Section 99242, whichever is later. However, the action need not be filed until September 15 if the action is with respect to a decision made prior to August 15 for the fiscal year which commenced on the July 1 immediately preceding such August 15.