(a) The authority may annually review and propose amendments to the county transportation expenditure plan adopted pursuant to Section 180206 to provide for the use of additional federal, state, and local funds, to account for unexpected revenues, or to take into consideration unforeseen circumstances.
(b) The authority shall notify the board of supervisors and the city council of each city in the county and provide them with a copy of the proposed amendments.
(c) The proposed amendments shall become effective 45 days after notice is given.