Chorleywood, Pinner, St Albans, Hemel Hempstead, Harefield, Edgware, Greenhill, Bovingdon, Ruislip, Harrow on the Hill, High Barnet, Chalfont St Giles, Barnet, Chalfont Saint Peter, Redbourn, Northolt, Chesham, Potters Bar, Amersham on the Hill, Gerrards Cross, Wembley, Hatfield, Hadley Wood.