M3 Junction 2-4a Smart Motorway
Hampshire and Surrey, UK · 2014–2017 (completed) · £129 million
The judgement call
Account-gated at launchPart of the initial wave of all-lane running smart motorways, which informed subsequent safety reviews and enhancements across the network. - The scheme aimed to increase capacity and improve journey reliability without traditional widening. - Subsequent retrofitting of additional emergency areas was undertaken due to safety concerns. - Demonstrated the challenges and benefits of implementing smart motorway technology.
Key engineering challenges
Converting the hard shoulder to a permanent running lane on a busy motorway. - Managing traffic flow and ensuring safety during construction on a critical route. - Integrating new technology for variable speed limits and traffic management. - Addressing public concerns regarding the safety of smart motorways.
Project facts
- Client / owner
- National Highways (formerly Highways England)
- Lead contractor
- Balfour Beatty Major Project
- Lead designers
- N/A (design was integrated into the project delivery)
- Project type
- upgrade
- Scale
- 13.4-mile (21.5 km) stretch converted to all-lane running; hard shoulder converted to a fourth lane.
- Disciplines
- civil; intelligent transport systems; electrical; geotechnical
- Standards & frameworks
- DMRB; CDM Regulations; Smart Motorway All-Lane Running standards
Sources: GOV.UK (https://www.gov.uk/government/publications/part-i-claim-m3-junction-2-to-4a-smart-motorway-scheme/m3-junction-2-to-4a-smart-motorway-scheme) - BBC News (https://www.bbc.com/news/uk-england-28722483) - Tensar (https://www.tensar.co.uk/success-stories/m3-junctions-2-to-4a) - National Highways (https://nationalhighways.co.uk/media/cpydvwzn/m3-junctions-2-to-4a-all-lane-running-one-year-post-opening-project-evaluation.pdf)