42 USC 7504 - Planning procedures

(a) In general 
For any ozone, carbon monoxide, or PM10 nonattainment area, the State containing such area and elected officials of affected local governments shall, before the date required for submittal of the inventory described under sections 7511a (a)(1) and 7512a (a)(1) of this title, jointly review and update as necessary the planning procedures adopted pursuant to this subsection as in effect immediately before November 15, 1990, or develop new planning procedures pursuant to this subsection, as appropriate. In preparing such procedures the State and local elected officials shall determine which elements of a revised implementation plan will be developed, adopted, and implemented (through means including enforcement) by the State and which by local governments or regional agencies, or any combination of local governments, regional agencies, or the State. The implementation plan required by this part shall be prepared by an organization certified by the State, in consultation with elected officials of local governments and in accordance with the determination under the second sentence of this subsection. Such organization shall include elected officials of local governments in the affected area, and representatives of the State air quality planning agency, the State transportation planning agency, the metropolitan planning organization designated to conduct the continuing, cooperative and comprehensive transportation planning process for the area under section 134 of title 23, the organization responsible for the air quality maintenance planning process under regulations implementing this chapter, and any other organization with responsibilities for developing, submitting, or implementing the plan required by this part. Such organization may be one that carried out these functions before November 15, 1990.
(b) Coordination 
The preparation of implementation plan provisions and subsequent plan revisions under the continuing transportation-air quality planning process described in section 7408 (e) of this title shall be coordinated with the continuing, cooperative and comprehensive transportation planning process required under section 134 of title 23, and such planning processes shall take into account the requirements of this part.
(c) Joint planning 
In the case of a nonattainment area that is included within more than one State, the affected States may jointly, through interstate compact or otherwise, undertake and implement all or part of the planning procedures described in this section.