A1 Leeming to Barton 

Upgrade 21km of the A1 into three-lane motorway to improve safety, reduce congestion and enhance journey time reliability. 

Project overview

2-stage open book, NEC2 Option-C, design and build. 

Morgan Sindall: Principal Contractor, responsible for: 

• Advanced works, including surveys 

• Design development (from preliminary design) 

• Construction, managing a subcontract workforce of 5,500 people 

• Managing stakeholder interfaces 

• Commissioning, testing and handover 

AECOM was Lead Designer and CDM Coordinator (now Principal Designer), with a 170-person project design team. 

We developed our Material Management Plan to maximise retention of earthworks arisings on site, taking 30,000 HGV movements off local roads and reducing 5,500tonnes CO₂e. For example, we: 

• Reused 100,000t of excavated material as capping 

• Retained an additional 600,000t of Class 2 material within the site boundary to restore an adjacent quarry to agricultural land 

We widened the Agricola bridge over the fast-rising River Swale (rises up to 3m in 20-minutes). We designed and built a temporary cofferdam using 1t gravel bags to provide safe, dry working areas for bridge works. We obtained Flood Defence Consent and operated a flood management plan with flood alert systems linked to live upstream river levels to enable workforce, plant and materials to be removed ahead of flood events. 

Previous flooding had resulted in closures of the A1. Preventing overland flow could be mitigated through bunding, but this would have directed flow towards populated areas. We designed a solution with the Environment Agency using 120,000t of site-won material to create embankments that impounded peak flows. We protected the A1 corridor, reducing flood risk in the Catterick area.