Following the recent discussions on redrawing the zone boundaries I decided
to work out what the boundaries would look like on a pure distance based
system. All stations were placed into zones according to their distance from
Charing Cross. The number of stations was kept constant so for each station
that moves in, one has to move out.

STATIONS MOVING IN
Zone 2 to Zone 1
Battersea Park, Camden Road, Camden Town, Kennington, Mornington Crescent,
Oval, Queenstown Road (Battersea)
Zone 3 to Zone 2
Balham, Cricklewood, Crouch Hill, Hampstead Heath, Harringay, Harringay
Green Lanes, Highgate, Stamford Hill, Streatham Hill, Tooting Bec, Tulse
Hill, Wandsworth Common, West Dulwich
Zone 4 to Zone 3
Anerley, Arnos Grove, Beckenham Hill, Finchley Central, Kent House, Lower
Sydenham, New Beckenham, New Southgate, Penge East, Penge West, Wembley
Park, Wembley Stadium, West Finchley
Zone 5 to Zone 4