Wiltshire Council's HGV route network map [on PDF] - still showing the A350 as a strategic lorry route.

The A350 is in fact a bad road for a long-distance lorry driver.  Only some short sections are really viable.

Most of the A350 is narrow, twisting, with poor visibility, subject to traffic lights and locally congested etc.

It will be observed that the A350 'strategic route' runs out of road at the A303.   The A350 at Shaftesbury and nearly to Blandford, about ten miles of tight twisty lane, is useless for HGVs.   If following the WC map, an HGV driver intending to get to the South Coast has to go through Salisbury, a choked-up heritage city.

It can be seen that the A350 'strategic route' is actually limited and is not the best way across Wiltshire.

Start/stop driving is also wasteful of fuel.   It is better to go a rather longer distance at a constant speed.

The realistic way for HGVs around the north to the south of Wiltshire and around this area of the South-West is via the M4, A34, M3 & M27, which are all top class roads.

This was a prime recommendation of the Bristol/Bath to South Coast Study.   The A350 was to be avoided.

The A34 was to be the south west inter-regional main north-south route and was to be signed accordingly.

This recommendation (not A350 bypasses...) was endorsed by the South West Regional Assembly, in 2004.

WC's Director of Environmental Services conceded to implementing new signage and a new HGV route map.

This has not been done; the map shown above is as it still appears on Wiltshire Council's website, in 2018.

Wiltshire Council seemed to want HGVs on the A350 to inflate a case for an A350 Westbury Bypass scheme.

The Wiltshire County Council Structure Plan hypes on that 'the A350 north/south acts as a route of regional and national importance for longer distance traffic between the Bournemouth/Poole area and Wales and the North and because of its strategic importance the route will be improved...'    But it does not mention that the A350 is fundamentaly unsuitable as a north/south HGV route of any strategic importance because of inherent severe constrictions of the natural terrain in a long section of the southern part of the A350.

Wiltshire Council is not the only body dragging its feet over a simple matter of better management.
When a 'strategic route' is unsuitable, this in itself is a false justification for building bypasses.