|Location Map ( geo)|
|From:||Brentwood By Pass (TQ623968)|
|To:||Chelmsford By Pass (TL677024)|
|Distance:||5 miles (8 km)|
|Meets:||A12, A1023, A12, A414|
|Route outline (key)|
The B1002 is the former route of the A12 through Mountnessing, Ingatestone and Margaretting. The numbering was changed in 1973 when the bypass of those places opened.
The B1002 starts from the grade-separated roundabout above the current A12 at the northern end of the Brentwood bypass. The A1023 is the re-numbered A12 on the other side of the roundabout into town. The B1002 heads northeast following the course of the Roman Road from London to Colchester, immediately reaching a roundabout for a local road junction and a 40mph limit for Mountnessing. That settlement is mostly ribbon development.
After Mountnessing, the original course is diverted because the A12 bypass switches from south of Mountnessing to north of Ingatestone and cuts the old route in two. So the B1002 now curves to the left, has a slip road on and off with the A12 northbound and then curves right to cross the bypass. The old Roman course is met again and that stump now provides a link to the A12 southbound. Just afterwards we meet the southbound exit sliproad from the A12 on the left and then run into a 30mph limit and Ingatestone.
The rather narrow High Street is negotiated and its then it's into an area with very large houses set well back from the road, which allows the NSL to be introduced. The road runs very near to the A12 bypass before curving to enter Margaretting and a 40mph limit. After Margaretting the road terminates back on the A12 at start of the Chelmsford Bypass, built in 1986. This is a dumbbell interchange and across the junction is the former route of the A12 through Chelmsford, now numbered as the A414.