|From:||East Finchley, London (TQ276886)|
|To:||Welwyn Garden City (TL235165)|
|Length:||21 miles (33.8 km)|
|Meets:||A1, A504, A406, A598, A1003, A109, A5109, A110, A411, A1081, A111, A1001, A414, A5129, A1(M)|
|Route outline (key)|
The greater part of the A1000 follows the former route of the A1 from East Finchley to Hatfield, as evidenced by many sections of it which are known as Great North Road.
Starting on the A1 north of Highgate the road heads north through East Finchley, after which there is a GSJ with the A406 North Circular. In North Finchley the road meets the A1003 and is forced left onto a gyratory, with northbound traffic using part of the A598 to return to the A1000 (southbound traffic follows the direct route). The road then continues through Whetstone, where it is briefly dualled, before reaching Barnet. After going under the Northern line the A1081 St Albans Road turns off left at traffic lights. Although both roads here have 4-digit numbers and seem quite unimportant this was once a major road junction as it was where the A6 turned off the A1.
After Barnet the road soon enters open country. This does not last for long, however, as the road soon goes under the M25 to enter Potters Bar. The road remains in a state of uncertainty as to whether it is urban or rural for a few more miles before reaching a fork GSJ on the southern edge of Hatfield. Ahead is the A1001 southern bypass whilst the A1000 has to TOTSO. Unusually for a GSJ, both roads are S2. The road now runs to the east of Hatfield New Town, parallel to the East Coast Main Line, before running through Old Hatfield to reach a set of traffic lights.
The route of the A1000 north of here has never been part of the Great North Road or the A1, and was built as the new town developed. The Great North Road from this point followed a straighter route past the west of the town and up to Welwyn along the B197, shown in this Google Maps extract. When originally inaugurated the A1000 continued ahead and soon met the A1 once more. However, it is no longer possible to follow this route; this is not necessarily due to urban development, more that the railway bridge collapsed in 1966 and was only rebuilt as a footbridge. The A1000 therefore TOTSOs right at the traffic lights to cross the A414 at a GSJ to reach the next New Town, Welwyn Garden City.
A wide S2 road liberally scattered with roundabouts takes the A1000 to the east of the town centre before reaching the Mundells gyratory, which includes a junction with the present alignment of the B1000. The A1000 then zigzags west to go under the Welwyn Viaduct (sometimes known as the Digswell Viaduct) and over the River Mimram to become D2. The road heads west for a short distance to reach A1(M) J6 where it also meets the Great North Road (now B197) once more. The south-facing and north-facing slip roads are a short distance apart so the A1000 follows the former A1 for a short distance to connect the whole of the junction.