Wichelstowe Southern Access Scheme
The Wichelstowe southern access road (WSA) is located to the southwest of Swindon and crosses the M4 motorway to the east of junction 16. The scheme will provide the fourth access to the Wichelstowe development and is a requirement of the planning permission for the wider Wichelstowe site. It will help support 4,500 new homes, the new district centre and will also unlock 12.5 hectares of employment land, supporting around 2,000 new jobs. See link to website of Swindon Borough Council for further information https://www.swindon.gov.uk/info/20136/transport_strategy/1050/wichelstowe_southern_access_scheme
This new road will consist of a new two lane carriageway (with footway / cycleway) between Hay Lane to the south of the M4 Motorway, crossing beneath the M4 and tying into South Leaze Track and will include the construction of a new roundabout to the south of the M4 which will be constructed offline with traffic then diverted onto this .
The existing Hay Lane to the east will then become a T Junction with through traffic, heading south, given the option to either take the first exit onto the new link road or take the second exit onto the B4005 Wharf Road.
The Link Road will then head north passing beneath the M4 Motorway, crossing agricultural land east towards South Leaze Track.
The M4 underpass will be constructed in three phases.
Initially, a new embankment will be constructed to the south of the M4 and the motorway will be moved onto this to allow construction of the northern section of the underpass. The M4 embankment will then be extended north and the southern section of the underpass will be constructed. Both temporary embankments will be in place at the same time to construct the north then south phases.
For a two kilometre section of the M4, 50mph speed restrictions will be in place as lanes are narrowed on the motorway. However, three lanes will be kept open in both directions at all times. The carriageways will be moved, one at a time, on to a widened opposite carriageway to allow work to take place on the edge of the motorway. This will involve utilising the temporary embankments on both sides of the motorway and moving the carriageways on to these embankments. The speed restrictions will be in place for approximately twelve months.
The third and shortest phase will involve splitting traffic to the east and westbound carriageways to allow the central section to be constructed, completing the underpass.
The scheme will be funded by central government through the Swindon and Wiltshire Local Enterprise Partnership (LEP) and the rest of the money put forward by Swindon Borough Council. Work is expected to be finished in the spring of 2021.