The M27 is located in Hampshire and falls within Highways England’s Area 3 Asset Support Contract, as well as the South East Regional Control Centre. It is a key part of the strategic road network, providing a vital transport link between Southampton and Portsmouth, while also connecting to the M3 at Junction 4, leading to Winchester and Basingstoke.

The M27 Junction 4 to 11 scheme is 24 kilometres (15 miles) long, and will include the eastbound and westbound M27 carriageways from the Hadrian Way overbridge at Junction 4 (the junction with the M3 at Southampton) to the Downend Road overbridge to the east of Junction 11 (the junction with the A27 at Fareham). It will also include the southbound linking carriageway from the M3, which joins the eastbound carriageway of the M27 at Junction 4.

This route currently faces congestion during peak travel hours caused by the volume of traffic using the network.

The scheme aims to:

• Reduce congestion and smooth the flow of traffic (by turning the hard shoulder into a permanent running lane)
• Improve journey time reliability on the strategic road network
• Support the economy and facilitate economic growth by providing increased capacity on the motorway
• Continue to deliver a high level of safety performance on the network
• Minimise environmental impacts of the scheme, and where possible allow for enhancements to be made to the environment

Junction 4 to 11 will be upgraded to dual four all-lane running. This will involve permanent conversion of the hard shoulder to create a fourth lane, and changing the junction slip roads to accommodate this. New CCTV cameras, electronic information signs and signals on gantries will show variable mandatory speed limits and manage traffic flow and incidents, while emergency areas will be in place throughout the length of the scheme.