(1) Each RTPO shall compile a regional transportation improvement program (TIP) at least once every two years. The regional TIP shall:

(a) Be developed on a cooperative basis by local government agencies, public transit agencies, and the department of transportation within each region;

(b) Consist of a list of regionally significant transportation projects and programs including projects proposed for construction and transportation demand management measures proposed to be implemented during each year for the next six-year period;

(c) Consist of regionally significant projects included in the local six-year transit development plans and six-year comprehensive transportation programs required by RCW 35.58.2795, 35.77.010, and 36.81.121 for transit agencies, cities, towns, and counties;

(d) Include all proposed WSDOT projects in the region;

(e) Include only projects consistent with the regional transportation plan;

(f) Include a financial section outlining:

(i) Sources of funding reasonably expected to be received for each year of the ensuing three-year period; and

(ii) All assumptions and explanations supporting the expected levels of funding consistent with information included in the financial component of the regional transportation plan.

(2) The six-year regional TIP developed by each RTPO is intended for use as a planning document and shall be available at the lead planning agency office of the RTPO.