|Location Map ( geo)|
|To:||Byard's Leap (SK989494)|
|Distance:||18.4 miles (29.6 km)|
|Meets:||A1, B676, A1, B1176, A52, A153, A17|
|Route outline (key)|
The B6403 is a medium-length B-road in southwest Lincolnshire.
The road starts on the A1 at the southern end of the Colsterworth bypass, with only a gap in the central reservation to allow access to/from the southbound carriageway. That road here runs along Ermine Street; we shall return to that later but for the time being we head northwest then north across the fields to enter Colsterworth itself. We quickly give way to the B676 then run along the High Street and back out into open country. The road then returns to the A1. Until 2008 it crossed it at grade but in that year a bridge was built and the gap in the central reservation closed. The road therefore continues ahead to become the northbound slip roads whilst the B6403 TOTSOs right to go over the A1 to reach a T-junction on joining the southbound slip road. We TOTSO right again.
We now head northeastwards along High Dike to reach Ermine Street which is now followed northwards, although this does not mean the road is completely straight. Presently we detour right to go under the East Coast Main Line, then bend sharply left on the far side to rejoin the Roman road. We continue across the open fields, passing no places of any size. Eventually a roundabout is reached, where we meet the A52 and B1176.
There's a multiplex ahead along the A-road but when it bears right the B6403 regains its number by turning left to continue north. On the far side we follow a dead-straight road for several miles across the fields. After passing RAF Barkston Heath we descend to reach the first place of any size on the Roman road, Ancaster. The A153 is crossed at traffic lights then we run along the main street before going under the Grantham to Sleaford railway line; Ancaster station is just to the left. After leaving town there are another few miles of straight road across open fields, after which the road bears to the right to end at a T-junction on the A17.
The B6403 came into being in the late 1920s to take over the original route of the A1 through Colsterworth after the A-road was moved onto its bypass. It was extended north to meet the A52 in 1935 and gained its present length in the 1940s.
Technically speaking, the B6403 should be a zone-1 road because virtually all of it does a zone-1 road's job, to all intents and purposes. When High Dike became classified (due to the building of airfields?) the planners merely extended the number that was already in the vicinity, namely the B6403, hence the apparent oddity of the number.