|Length:||25.2 miles (40.6 km)|
|Meets:||A33, A3024, A35, M271, A27, A3090, A30, A303, A343, A3093|
|Former Number(s):||B3042, A342|
|Route outline (key)|
Southampton - Andover
The road starts on the A33 by Southampton Central station, heading over the railway and then turning northwest to head along Shirley High Street. This part of the road is frequently congested.A35 at traffic lights and heads into more suburban areas, passing the Ordnance Survey offices. There's then a bridge over the M27, followed by a roundabout where the M271 terminates.
From here, the road changes to a winding rural road. After a few miles, the A27 arrives from the east, and the A3057 multiplexes with it past Broadlands House towards Romsey. There's a roundabout where the A27 leaves and our multiplex changes to the A3090, which leaves at the next roundabout by the old cinema; in both cases the A3057 is the junior partner.
In Romsey itself, there's a confusing array of TOTSOs to get back out into the countryside, then it's a pleasant drive along the Test Valley through King's Sombourne to Stockbridge. There's a brief multiplex with the A30 east of the High Street, then it's back into the country. The road bends sharply left after a few miles to cross the Test, after which our final section is along the Anton Valley, where the B3420 appears from the right. There's a GSJ with the A303 Andover Bypass, before the road finishes in the town centre with the A343. Maps claim that the whole of the ring road is actually numbered A3057.
The A3057 was originally numbered as the B3042 from Southampton to today's junction with the B3420 (then part of the A342), and then A342 to Andover. The B3042 was upgraded to A3057 very early on, probably on 1st April, 1925, while the remainder of the route was renumbered on 1st April, 1933.
The multiplex with the A27 south of Romsey dates from the 1950s, when the A27 was diverted from a more built up route further east.