(1)
In general.—
Each metropolitan planning organization shall prepare and update a transportation plan for its metropolitan planning area in accordance with the requirements of this subsection. The metropolitan planning organization shall prepare and update such plan every 4 years (or more frequently, if the metropolitan planning organization elects to update more frequently) in the case of each of the following:
(A)
Any area designated as nonattainment, as defined in section 107(d) of the Clean Air Act (42 U.S.C. 7407
(d)).
(B)
Any area that was nonattainment and subsequently designated to attainment in accordance with section 107(d)(3) of that Act (42 U.S.C. 7407
(d)(3)) and that is subject to a maintenance plan under section 175A of that Act (42 U.S.C. 7505a).
In the case of any other area required to have a transportation plan in accordance with the requirements of this subsection, the metropolitan planning organization shall prepare and update such plan every 5 years unless the metropolitan planning organization elects to update more frequently.