A303 Stonehenge tunnel (Amesbury to Berwick Down)
Wiltshire, UK · Planning/Early Works (c. 2013-2024); DCO revoked March 2026 · £1.7 billion (estimated cost before cancellation); £179.2m spent on development before cancellation
The judgement call
Account-gated at launchThe project's Development Consent Order (DCO) was revoked in March 2026 due to financial reasons and a determination that it no longer aligned with strategic policy objectives, despite earlier approvals. - Significant public and legal challenges from heritage groups and environmentalists regarding the impact on the World Heritage Site. - Highlights the complexities and political sensitivities of major infrastructure projects in historically significant areas. - Substantial investment in planning and archaeological fieldwork was made before cancellation.
Key engineering challenges
Constructing a tunnel beneath a UNESCO World Heritage Site, requiring extreme care to protect archaeological integrity and the landscape. - Managing complex ground conditions and hydrogeology in the vicinity of the monument. - Balancing the need for improved transport links with environmental and heritage protection. - Extensive archaeological investigations and mitigation measures.
Project facts
- Client / owner
- National Highways
- Lead contractor
- N/A (main construction not started)
- Lead designers
- Arup, Atkins (involved in earlier design stages)
- Project type
- new build (cancelled)
- Scale
- Proposed 12.8km dual carriageway, including a 3.3km tunnel (3km deep bored, 0.3km cut and cover) under the Stonehenge World Heritage Site.
- Disciplines
- civil; structural; geotechnical; environmental; archaeological
- Standards & frameworks
- DMRB; CDM Regulations; UNESCO World Heritage Site guidelines
Sources: BBC News (https://www.bbc.com/news/articles/c7959v897n9o) - New Civil Engineer (https://www.newcivilengineer.com/latest/stonehenge-tunnel-dco-officially-revoked-as-it-no-longer-aligns-with-strategic-policy-objectives-18-03-2026/) - National Trust (https://www.nationaltrust.org.uk/who-we-are/news/stonehenge-a303-road-improvement-scheme)