M4 Junction 3-12 Smart Motorway
Berkshire, UK · 2018–2022 (completed March 2022) · £848 million
The judgement call
Account-gated at launchPart of the wider Smart Motorways Programme aimed at increasing capacity and improving journey reliability. - Involved significant structural works to accommodate new gantries and technology. - The project was subject to scrutiny regarding smart motorway safety, leading to ongoing reviews and enhancements across the network. - The scheme aimed to smooth the flow of traffic and reduce congestion without traditional widening.
Key engineering challenges
Converting a long and heavily used section of the M4 to an all-lane running smart motorway. - Managing traffic flow and ensuring safety during construction on a critical route connecting London and South Wales. - Integrating complex technology for variable speed limits and traffic management. - Addressing public concerns regarding smart motorway safety and implementing safety enhancements.
Project facts
- Client / owner
- National Highways (formerly Highways England)
- Lead contractor
- Balfour Beatty Vinci JV (BBV JV)
- Lead designers
- N/A (design was integrated into the project delivery)
- Project type
- upgrade
- Scale
- 32 miles (51 km) of all-lane running smart motorway; conversion of hard shoulder to a live lane; installation of new technology, gantries, and emergency areas.
- Disciplines
- civil; intelligent transport systems; electrical; environmental
- Standards & frameworks
- DMRB; CDM Regulations; Smart Motorway All-Lane Running standards
Sources: National Highways (https://nationalhighways.co.uk/our-roads/south-east/m4-junctions-3-12/) - Balfour Beatty (https://www.balfourbeatty.com/what-we-do/projects/m4-smart-motorway/) - VGC Group (https://vgcgroup.co.uk/case-studies/m4-smart-motorway/) - Institution of Civil Engineers (ICE) (https://www.ice.org.uk/events/recorded-lectures/m4-junctions-3-to-12-upgrade-to-smart-motorway)