(1) Funds collected under RCW
81.100.030 or
81.100.060 and any investment earnings accruing thereon shall be used by the county or the regional transportation investment district in a manner consistent with the regional transportation plan only for costs of collection, costs of preparing, adopting, and enforcing agreements under RCW
81.100.030(3), for construction of high occupancy vehicle lanes and related facilities, mitigation of environmental concerns that result from construction or use of high occupancy vehicle lanes and related facilities, payment of principal and interest on bonds issued for the purposes of this section, for high occupancy vehicle programs as defined in RCW
81.100.020(5), or for commuter rail projects in accordance with RCW
81.104.120. Except for funds raised by an investment district, no funds collected under RCW
81.100.030 or
81.100.060 after June 30, 2000, may be pledged for the payment or security of the principal or interest on any bonds issued for the purposes of this section. Not more than ten percent of the funds may be used for transit agency high occupancy vehicle programs.
(2) Notwithstanding the limitations in this chapter, a regional transportation investment district may use funds collected under RCW
81.100.030 or
81.100.060 and any investment earnings accruing thereon for projects contained in a plan developed under chapter
36.120 RCW. These expenditures shall not be limited to high occupancy vehicle systems.
(3) Priorities for construction of high occupancy vehicle lanes and related facilities shall be as follows:
(a)(i) To accelerate construction of high occupancy vehicle lanes on the interstate highway system, as well as related facilities;
(ii) To finance or accelerate construction of high occupancy vehicle lanes on the noninterstate state highway system, as well as related facilities.
(b) To finance construction of high occupancy vehicle lanes on local arterials, as well as related facilities.
(4) Moneys received by a county under this chapter shall be used in addition to, and not as a substitute for, moneys currently used by the county for the purposes specified in this section.
(5) Counties and investment districts may contract with cities or the state department of transportation for construction of high occupancy vehicle lanes and related facilities, and may issue general obligation bonds to fund such construction and use funds received under this chapter to pay the principal and interest on such bonds.