§ 51.400 - Frequency of conformity determinations.

(a) Conformity determinations and conformity redeterminations for transportation plans, TIPs, and FHWA/FTA projects must be made according to the requirements of this section and the applicable implementation plan.

(b) Transportation plans. (1) Each new transportation plan must be found to conform before the transportation plan is approved by the MPO or accepted by DOT.

(2) All transportation plan revisions must be found to conform before the transportation plan revisions are approved by MPO or accepted by DOT, unless the revision merely adds or deletes exempt projects listed in § 51.460. The conformity determination must be based on the transportation plan and the revision taken as a whole.

(3) Conformity of existing transportation plans must be redetermined within 18 months of the following, or the existing conformity determination will lapse:

(i) November 24, 1993;

(ii) EPA approval of an implementation plan revision which:

(A) Establishes or revises a transportation-related emissions budget (as required by CAA sections 175A(a), 182(b)(1), 182(c)(2)(A), 182(c)(2)(B), 187(a)(7), 189(a)(1)(B), and 189(b)(1)(A); and sections 192(a) and 192(b), for nitrogen dioxide); or

(B) Adds, deletes, or changes TCMs; and

(iii) EPA promulgation of an implementation plan which establishes or revises a transportation-related emissions budget or adds, deletes, or changes TCMs.

(4) In any case, conformity determinations must be made no less frequently than every three years, or the existing conformity determination will lapse.

(c) Transportation improvement programs. (1) A new TIP must be found to conform before the TIP is approved by the MPO or accepted by DOT.

(2) A TIP amendment requires a new conformity determination for the entire TIP before the amendment is approved by the MPO or accepted by DOT, unless the amendment merely adds or deletes exempt projects listed in § 51.460.

(3) After an MPO adopts a new or revised transportation plan, conformity must be redetermined by the MPO and DOT within six months from the date of adoption of the plan, unless the new or revised plan merely adds or deletes exempt projects listed in § 51.460. Otherwise, the existing conformity determination for the TIP will lapse.

(4) In any case, conformity determinations must be made no less frequently than every three years or the existing conformity determination will lapse.

(d) Projects. FHWA/FTA projects must be found to conform before they are adopted, accepted, approved, or funded. Conformity must be redetermined for any FHWA/FTA project if none of the following major steps has occurred within the past three years: NEPA process completion; start of final design; acquisition of a significant portion of the right-of-way; or approval of the plans, specifications and estimates.