When used in this act:

(a) “Transportation system” means all plants, equipment, property and rights useful for transportation of passengers for hire except taxicabs and except all transportation facilities extending beyond the boundaries of the metropolitan area and includes, without limiting the generality of the foregoing, street railways, subways and underground railroads, motor vehicles, trolley buses, motor buses and any combination thereof.

(b) “Authority” means the transit authority created by this act.

(c) “Board” means the transit board created by this act.

(d) “City” means the city of Topeka, Kansas.

(e) “Mayor” means the mayor of Topeka, Kansas.

(f) “Motor vehicle” means every vehicle which is self-propelled.

(g) “Metropolitan area” includes the area within the corporate limits of the city of Topeka, Kansas and includes the area having a radius within 90 miles from the corporate limits of such city.