Oregon constitution
Article XI: corporations and internal improvements
Section 13

Notwithstanding the provisions of section 20, Article I, section 10, Article VI, and sections 2 and 9, Article XI, of this Constitution, when any city, county, political subdivision, public agency or municipal corporation assumes responsibility for the operation of a public transportation system, the city, county, political subdivision, public agency or municipal corporation shall make fair and equitable arrangements to protect the interests of employes and retired employes affected. Such protective arrangements may include, without being limited to, such provisions as may be necessary for the preservation of rights, privileges and benefits (including continuation of pension rights and payment of benefits) under existing collective bargaining agreements, or otherwise.