Those parts of Northamptonshire, Bedfordshire, Buckinghamshire, Cambridgeshire, Leicestershire, Lincolnshire and Rutland bounded by:
On the North the A4304 from M1 (junction 20, near Lutterworth) and via Market Harborough, to A6 at Great Bowden. B664, A6003 to Uppingham. A6003, A47, A6121 to Stamford and the A16 to Deeping Gate. On the East by A15 to the A47 at Walton. Around Peterborough to the east via A47, A1139, A15 to Normans Cross, the old A1 to Alconbury, B1043 through Little and Great Stukeley to A141. On the South the A141, A14 to A14/A1 junction at Brampton, A1, B661, B645, B660 to Bedford, A428, A422 to A422 / A509 JUNCTION. Straight line to junction of A508 and Grafton Way. A508, to A5 at Old Stratford and the A422, A421, A4421 to Bicester. On the West the B4100, B4031, B4100, A4260 to Banbury, A361, A45, A425, A361 via Daventry to Kilsby. The A5 to A426 to Junction 20(M1) near Lutterworth.