(1) By December 31, 1996, each RTPO shall certify, that the transportation element of all comprehensive plans for cities and counties planning under the Growth Management Act:

(a) Reflect the transportation guidelines and principles established in the regional transportation plan;

(b) Are consistent with the adopted regional transportation plan; and

(c) Conform with the requirements of RCW 36.70A.070.

(2) Each RTPO shall also certify that county-wide planning policies adopted under RCW 36.70A.210 and the adopted regional transportation plan are consistent.

(3) Regions shall cooperatively define and establish measures and processes to determine regional consistency with the adopted regional transportation plan.