Cal. Pub. Util. Code § 142261

If a retail transactions and use tax is adopted pursuant to this chapter, the authority shall prepare and submit a report to the Department of Transportation, to the board of supervisors, to the city council of each city in the county, and to the transportation planning agency, on or before each January 1 after taxes are imposed pursuant to this chapter. The report shall evaluate and report the progress made in implementing the expenditure plan during the preceding fiscal year.