4. The commission may enter into contracts or agreements with the counties and cities within the transportation district, with counties and cities that adjoin the transportation district and are within the same planning district, or with other commissions of adjoining transportation districts to provide, or cause to be provided, transit facilities and service to such counties and cities or to provide transit facilities and other modes of transportation between adjoining transportation districts. Such contracts or agreements, together with any agreements or leases for the operation of such facilities, may be utilized by the transportation district to finance the construction and operation of transportation facilities, and such contracts, agreements, or leases shall inure to the benefit of any creditor of the transportation district. However, except in any transportation district containing any or all of the Counties of Chesterfield, Hanover, and Henrico or the City of Richmond, being so delegated by the respective local governments, the commission shall not have the power to regulate services provided by taxicabs, either within municipalities or across municipal boundaries, which regulation is expressly reserved to the municipalities within which taxicabs operate. In any transportation district containing any or all of the Counties of Chesterfield, Hanover, and Henrico or the City of Richmond, the commission may, upon proper authority granted by the respective component governments, regulate services provided by taxicabs, either within localities or across county or city boundaries.