Except such powers as are conferred by law upon the Board, or such services as are performed by the Department of Transportation pursuant to law, the Director of the Department of Rail and Public Transportation shall have the power to do all acts necessary or convenient for establishing, maintaining, improving, and promoting public transportation, transportation demand management, ridesharing, and passenger and freight rail transportation in the Commonwealth and to procure architectural and engineering services for rail and public transportation projects as specified in § 2.2-4303.1.