M25 Junction 5-7 Smart Motorway
Surrey & Kent, UK · 2012–2014 (opened April 2014) · N/A (described as cost-effective, specific figure not readily available)
The judgement call
Account-gated at launchThis was the first all-lane running smart motorway scheme, serving as a pilot for future projects. - Post-opening evaluations highlighted issues such as lower lane 1 flow and the need for more emergency refuge areas, leading to subsequent safety enhancements across the smart motorway network. - The project demonstrated the potential for increasing capacity without traditional widening, but also exposed challenges in public perception and safety design. - The scheme aimed to improve journey time reliability and reduce congestion on a critical section of the M25.
Key engineering challenges
Implementing the first all-lane running smart motorway scheme on the M25. - Managing traffic flow on one of the busiest motorways in Europe during construction. - Integrating new technology and signage to manage variable speed limits and lane closures. - Addressing initial public and operational concerns regarding the safety and functionality of all-lane running.
Project facts
- Client / owner
- National Highways (formerly Highways England)
- Lead contractor
- N/A (likely part of a larger framework, specific contractor not explicitly stated in readily available sources)
- Lead designers
- N/A (likely part of a larger framework, specific designer not explicitly stated in readily available sources)
- Project type
- upgrade
- Scale
- 12.2 miles (19.6 km) of all-lane running smart motorway; conversion of hard shoulder to a live lane.
- Disciplines
- civil; intelligent transport systems; electrical
- Standards & frameworks
- DMRB; CDM Regulations; Smart Motorway All-Lane Running standards
Sources: National Highways (https://nationalhighways.co.uk/media/k5sfyq31/m25-junctions-5-to-7-five-year-post-opening-project-evaluation.pdf) - GOV.UK (https://www.gov.uk/government/publications/m25-junction-5-to-7-third-year-evaluation-report) - The AA (https://www.theaa.com/about-us/newsroom/review-of-m25-smart-motorway-schemes)