I live in a village that has a station with direct links to London. Several satellite villages and communities in about a three mile radius don't so lots of people drive to the station to commute. There is such an array of accents. Some Berkshire accents are quite cockney-like and others very rural with quite a burr. Many are indistinctive but many of the commuters speak like they chewed on a full bowl of plums for breakfast so I would err towards social class and background more than geography and climate given the distance from the station.