Those parts of Greater London, Kent, Surrey, East Sussex and West Sussex bounded by:

On the North by the Thames from Westminster Bridge to London Bridge. On the East the A2, A20 to Lewisham, A21 to Badgers Mount, A224 to Riverhead, A25 to M25 link road (junction 5), the A21 to Hastings. On the West the A284 from Littlehampton, A27 to Arundel, A284, A29, B2138, A283 via Petworth to Milford. The A3 from Milford to north of Guildford and then via B2215 through Ripley.  A3 to the crossing point with the A307 north of Cobham.  A307 via Esher to Kingston-upon-Thames and A308, A3 to the Thames at Westminster Bridge.