A35 Road and Bridge Essential Works (Redbridge Viaduct)

Last update: June 2021

Latest updates

Ahead of Hampshire County Council’s third phase of works to repair the structures that support the A35 Redbridge Causeway, SGN will be carrying out investigative works to confirm the position of the existing gas main and to determine the best method for relocating it.

Dates and details of the closures

Phase 1 - Friday 25 June until Thursday 1 July 2021

Overnight closures (8pm to 5am each day). One lane of the eastbound A35 will be closed on the approach to the Totton on-slip and moved across to the right-hand lane to allow for a shortened, dedicated Totton on-slip in the left-hand lane. A temporary 30mph speed limit will be in force. SGN’s work will be carried out at night only with all traffic management being removed during the day.

Phase 2 - Friday 2 July to Monday 5 July

Whole weekend closure (from 8pm on Friday to 5am on Monday). A full closure of the A35 eastbound off-slip to Redbridge Roundabout will be in place with a signed diversion taking road users to the next junction at the Millbrook Roundabout and back onto the westbound carriageway of the A35.

Phase 3 – Monday 5 July to Thursday 8 July

Overnight closures (8pm to 5am each day). The left-hand lane of the eastbound A35 will be closed from the approach to the Totton on-slip until the start of the off-slip to Redbridge Roundabout. The Totton on-slip will be narrowed / shortened and will merge with the single lane of eastbound A35 traffic in the right-hand lane. A temporary 30mph speed limit will be in force. All traffic management will be removed during the day.

Throughout all three phases, the footpath will be closed and a signed, diversion for pedestrians will be in place.


Hampshire County Council’s contractor Milestone Infrastructure is progressing well on repairs to the underside of Redbridge Viaduct whilst working under tidal conditions and in line with the latest Government guidance with regards to COVID-19 safety.

The works are part of a much wider project to refurbish all four structures carrying the A35 Redbridge Causeway, and follow the first phase of repair works which were completed in 2018. All four structures which make up the Causeway need repair and the County Council has submitted a funding bid to Government to contribute to the costs.

The repairs, which commenced in January 2020 and are highly weather dependant, are being sequenced to limit propping and closures of the A35 above. They are expected to take approximately 18 – 20 months to complete.

Structures in this phase are:

  • Redbridge Viaduct, which carries the A35 Westbound carriageway between M271 Redbridge Roundabout and Totton
  • Redbridge Road bridge which carries the A35 Eastbound carriageway over Test Lane/Old Redbridge Road, Southampton

On completion the repair work will protect over 100 concrete supports and include a cathodic protection system which will help prolong the life span of the structures.

Redbridge Viaduct is a 50 year-old bridge carrying westbound traffic in and out of Southampton over Test Lane, the railway and the River Test. Due to its age, the harsh marine environment and the large volumes of traffic that use this bridge it requires essential repairs to the concrete supports. The viaduct is 270 metres long and is supported on nine reinforced concrete wall supports and 106 columns (piles).

Where the work is taking place

Redbridge location map

When the work is taking place

The A35 will be open at all times during the works unless in emergency situations. For short periods during construction, there may be off-peak temporary lane closures during deliveries of materials or other necessary work.

As part of the scheme, Test Lane/Old Redbridge Road in Southampton will be closed to traffic to facilitate works on the either side of the road supports in early 2021.

The programme for this closure and diversion has been agreed in collaboration with Southampton City Council with due regard to the ongoing neighbouring works to the M271 Redbridge Roundabout Improvements. Further details and dates will be available once confirmed.

The footway / cycleway on the southern side of the Viaduct will be closed to the public for approximately four months and a signed diversion route for pedestrians and cyclists will be in place. This is facilitate the installation of cathodic protection cabling and testing. The exact dates of the closure will be advertised on site in advice and are expected to be over winter 2020/21.

Economy, Transport and Environment Department
Hampshire County Council
The Castle

SO23 8UD