A1(M) Hatfield Tunnel Refurbishment

The A1(M) through Hatfield Tunnel forms part of the Trans-European Road Network. The existing Hatfield Tunnel is located between Junctions 3 and 4 on the A1(M). The tunnel passes beneath Cavendish Way to the south and Green Lanes roundabout to the north and runs parallel to the A1001.

The Hatfield Tunnel is a twin bore reinforced concrete portal frame structure and was constructed in 1985. The tunnel is approximately 1,147m long between the south and the north portals.

Refurbishment is required because the tunnel's mechanical and electrical systems are at the end of their design life and to upgrade tunnel equipment in line with new standards. New monitoring equipment will be installed and linked to the new control systems in the Highways Agency’s Regional Control Centre.

Improvement for the Hatfield Tunnel Refurbishment Project will be carried out in the following major phases:

• Phase 1 (11 weeks) Lowering of existing emergency exit doors.
• Phase 2 (40 weeks) Closure of Northbound Bore. Complete replacement of the mechanical and electrical equipment.
• Phase 3 (40 weeks) Closure of Southbound Bore. Complete replacement of the mechanical and electrical equipment.
• Phase 4 (1 week) Finishing works to the central reservation and replacement of barriers.

What will we be doing:

• Works will be carried out within the existing highway boundary.
• Upgrading and the full refurbishment of the tunnel equipment in line with current standards and new legislation.
• Additional operational safety measures and introduction of passive fire protection of structure.
• Removal of existing handrails

Each bore of the tunnel will be completely closed to traffic during its refurbishment. During this period the other bore will accommodate four lanes operating with a contraflow, with a reduced maximum mandatory speed limit. It may be necessary to occasionally undertake certain activities overnight, during a complete closure of the whole tunnel, with mainline traffic diverted on to the A1001.

In the spring of 1983, work started at Hatfield on the alterations to gas, electricity and water mains, sewers and telephone equipment etc.

In spring 1984 , construction work commenced.

Hatfield Tunnel Opened on the 10 December 1986 by the Duke of Kent.

The 1,147m long tunnel is a cut-and-cover structure constructed east of the existing A1 between Cavendish Way and the Green Lanes Roundabout. The tunnel accommodates the full motorway formation width with a continuous separating wall along the motorway centre line.