United Kingdom – The GBP75 million scheme to tackle congestion at M25 Junction 25 and improve the operation and maintenance of the M25 Holmesdale Tunnel will start on Saturday May 6th 2006 and is due to be completed by Christmas 2007.

The scheme will upgrade the mechanical and electrical equipment installed in the Holmesdale tunnel to improve its operation and maintenance, and will increase the number of lanes on the eastbound (clockwise) M25 carriageway at Junction 25 from two to three. The work will be carried out in five phases.

• Phase one will see refurbishment of the central tunnel wall with two lanes of traffic running through each tunnel bore. It will last 17 weeks.
• The second phase will see a complete refurbishment of the equipment in the eastbound (clockwise) tunnel bore and construction of a third lane; the eastbound tunnel bore will be totally closed to traffic, with two lanes running in each direction in the westbound tunnel bore for a period of 28 weeks.
• Phase three, another 28 week period, consists of a complete refurbishment of the equipment in the westbound (anti-clockwise) tunnel bore; the westbound tunnel bore will be totally closed to traffic, with two lanes running in each direction in the newly refurbished eastbound tunnel bore.
• Phases four and five will see finishing work to the central reservations and replacement of the safety barriers and two lanes of traffic running through each tunnel bore for six weeks.

The eastbound (clockwise) entry slip road and the westbound (anti-clockwise) exit slip road at Junction 25 will be closed during the whole of the 18-month scheme.

Highways Agency project manager Eamonn Colgan said: "Once completed the improvement at Junction 25 will reduce congestion and improve safety for drivers using the tunnel. The new mechanical and electrical equipment in the tunnel will reduce the number of unplanned maintenance closures currently required.

"Drivers are advised to plan their journeys, and allow extra time if possible because there will be narrow lanes, a contraflow and a speed limit of 40mph through the works area for the safety of drivers and workers. Users of the M25 should remain on the motorway and follow the dedicated diversion routes if necessary. Please drive safely and obey the temporary 40mph speed limit signs."