|Location Map ( geo)|
|Distance:||16.3 miles (26.2 km)|
|Meets:||A340, A3010, B3051, B3048, A3093|
|Route outline (key)|
The route now starts at the Thornycroft Roundabout on the A340, the western section of the Basingstoke Ring Road, where it also meets the A3010. There is a short section of (now 50mph) dual carriageway before the road reaches the oval West Ham Roundabout (the odd shape is partially due to the location of a fire station directly exiting onto the roundabout). The route continues on as a (now 40mph) single carriageway built in the 1970s as part of the town expansion works. After the next roundabout the road joins its original alignment as it passes (at 30mph) through Buckskin and Worting.
The route continues under a narrow and low bridge under the South West Mainline railway, before meeting Roman Way a link to the A339 at a mini roundabout. The route leaves the built up area and there is a short stretch in open countryside (NSL) before the village of Newfoundland is reached. To the west of the village, Pack Lane, which follows the route of the Harrow Way, joins at a T-junction.
As we bear left to go under the railway line, the Harrow Way continues ahead. We continue across open country and soon reach Overton where the road shows its history by entering town along London Road. The B3051 turns right at traffic lights and then we go along the High Street to leave town. There's a diversion round the southern edge of Laverstoke Park. We pass Laverstoke Mill, now the Bombay Sapphire gin distillery, before crossing Freefolk Bridge over the River Test. The village of Freefolk is on the far side and then we follow the river downstream to reach Whitchurch, again entering town along London Road.
A T-junction in the town centre marks the original meeting point of the A30 and A34 - but both roads now avoid the town. The B3400 TOTSOs left and then continues ahead at a mini-roundabout to run along Church Street. After going round two sides of the church we go under a disused railway bridge and then go under the A34 Whitchurch bypass. There is no junction here; traffic to/from the south can use the ex-A34 south of the mini-roundabout but traffic heading north has to travel a couple of miles before reaching the GSJ just south of Litchfield.
Continuing west, there's a bit more of the flood plan of the River Test to cross before we go over the Bourne Rivulet to reach Hurstbourne Priors, where the B3048 crosses at a staggered crossroads; the majority of the village lies along that road. It's then back into open country again and the road crosses open fields with several tree-lined sections. After going through Andover Down the road reaches Andover proper, where it ends at a roundabout on the A3093 eastern bypass.
The B3400 was created on 1st April, 1933, following the diversion of the A30 via the original Basingstoke Bypass and Stockbridge. It was probably the first instance of a road number being created "out of sequence" as no B339x roads existed at this time (though road numbers had been recycled as early as 1926).
The original start point in Basingstoke, before the New Town was created, was at the junction of Sarum Hill and Winchester Road. It ran down the hill and westward along Worting Road, rejoining its current course.