Highways England is costing out plans to widen the proposed A303 Stonehenge Tunnel to create a hard shoulder on the dual carriageway scheme.
Consultants are being asked to investigate the impact of adding emergency refuges or an additional hard shoulder in order to increase tunnel safety over the 3km bored tunnels, reports Construction Enquirer.
Work is being undertaken six months after three consortia were shortlisted to bid for the £1.7bn project to ease congestion on the A303 between Amesbury and Berwick Down and allow traffic to travel under the World Heritage Site. These are BMJV-Bouygues Travaux Publics and J Murphy & Sons, HDJV – Hochtief Infrastructure and Dragados and MORE JV – FCC Construcción Salini Impregilo and BeMo Tunnelling UK
Consultants are being asked to cost the option of two laybys per tunnel, spaced at 1000m centres, constructed using sprayed concrete lining techniques, or increasing the diameter of the tunnels to incorporate a hard shoulder lane over the entire length of the tunnel.
Pic-Construction Enquirer/Highways England