“Public transit corridor” means that area within one-quarter mile of a route on which the level of service is at or above the average for the transit system as a whole, according to the transit operator serving the area, and on which regularly scheduled public mass transit service stops are located, or within one-quarter mile of an existing or planned public mass transit guideway or busway station, or within one-quarter mile of a multimodal transportation terminal serving public mass transit operations. “Level of service,” unless otherwise defined by the transit operator, means the frequency of headways and the number of vehicles per day.