As used in this chapter:
(a) “Establish” includes establish, construct, complete, acquire, extend or reroute. It does not, however, include the maintenance and operation of any existing system by the district.
(b) “Existing system” means any transit service or system of a publicly or privately owned public utility situated entirely within the district or at least 75 percent of whose revenue vehicle miles for the preceding calendar year were operated within the district.