Oregon Revised Statutes Highways, Roads, Bridges and Ferries § 366.522

It hereby is declared to be the policy and intent of the Legislative Assembly that the total appropriations out of the State Highway Fund made by it for the payment of expenses incurred by the Legislative Assembly by and through its interim committee during any biennium shall be deemed to be the maximum amount necessary for such purpose. Any unexpended and unobligated balance remaining in any such appropriation heretofore or hereafter made shall, after the expiration of the biennium for which the appropriation was made, be returned to the State Highway Fund and may thereafter be used for any purpose authorized by law.