Change Route: A1(M) North or A1 South

Also exit here for London North West & Services. The A1(M) was extended south past Hatfield, through a cut and cover tunnel topped off with a shopping complex, to meet the M25. The next section is oldest part of the M25. Up to J24 (planned as the M16 but opened as an all-purpose road) opened in September 1975 at a cost of £4.9m (what a bargain!).