Highways Agency

• A3 Hindhead Improvement

A3 Hindhead Improvement

Description and Plan of the Project

The new dual two lane carriageway will start about 900m south of the end of the existing dual carriageway at Hammer Lane. South of Hammer Lane the southbound carriageway will be moved into the existing central reserve and the old southbound carriageway retained as a two way service road. The northbound carriageway will remain on its present line. North of Hammer Lane the new A3 will swing across the line of the existing A3 to run on its southeast side. Hammer Lane will pass under the new A3 and connect with the existing single carriageway A3 which will be retained for local access. There will be a new local road on the southeast side of the new A3 connecting High Pitfold to Hammer Lane and an underpass at High Pitfold for walkers, cyclists and horseriders.

View of the existing dual carriageway

The main grade-separated junction will be located at Hazel Grove and will cater for all movements, with the new A3 in cutting. 

Beyond Hazel Grove the new A3 will swing eastwards through woodland in cutting up to 18m deep before crossing part of Tyndall’s Wood on embankment up to 10m high.

The road will then pass under the east side of Tyndall’s Wood, the A287 and the Devil’s Punch Bowl SSSI in a 1.9 km long twin bored tunnel to emerge in Boundless Valley. The portals will be the only visible parts of the tunnel.

The new A3 will head northwards in Boundless Valley, mostly on shallow embankment, climbing gradually to join the existing road about 400m north of the existing end of the dual carriageway.

Boundless Road will be taken under the new A3 and continue as the new Boundless to Thursley link road, which will be a narrow single carriageway. This will run just to the west of the trunk road northwards to Thursley Junction.

The existing A3 between the National Trust car park and the Youth Hostel access will be closed and the Punch Bowl landscape reinstated. The section between the Youth Hostel access and the Boundless to Thursley link road will become a bridleway, cycleway and private means of access to the Youth Hostel and nearby cottages. The existing byway (BOAT 500, Old Portsmouth Road) will have a 3m wide paved cycleway. The scheme will create a 4.5km continuous route for cyclists, equestrians and walkers, away from main road traffic, running from Hindhead Crossroads to Thursley Junction. South of Thursley, a new underpass will cater for users of the Greensand Way and provide local access. This will enable the two existing minor road junctions and the associated central reserve gaps to be closed.

A detailed plan and further information is available in the A3 Hindhead Explanation of the May 2004 Scheme and Non-Technical Summary (PDF 529KB)

General Questions About the Scheme

Q. How long is the overall scheme?

A. The new dual carriageway road will be about 6.5km long, but if you include the additional underpasses which are to be built near Rectory Lane to the south of the scheme and at Greensand Way to the north, the works will extend for a total of about 9 km along the A3.

Q. How long will it take to build the scheme?

A. It will take about four years from start of construction to opening the tunnel for traffic. After the tunnel is opened there will be another six to nine months work to remove the existing A3 from around the Punch Bowl.

Q. Why does it take so long?

A. It takes so long because our construction programme is designed to reduce disruption locally. For example, to minimise the effect on the majority of residents, we are planning to construct the tunnels from the northern end. We will also move the large amounts of spoil from the south to the north through the tunnel to avoid disrupting the local road network. Once the tunnels are built it is essential that we take sufficient time to install, commission, integrate and test the safety critical systems of the tunnel, to the satisfaction of the emergency services. This will include a full scale emergency exercise before the tunnel opens to traffic.

Q. How much will the scheme cost?

A. The scheme budget which includes all the costs of preparation, design, construction, acquiring land, VAT and inflation is £370m.

Q. Why has the cost gone up so much since the public inquiry?

There are two main reasons for the increase in the scheme budget:

• additional inflation costs due to the delay in the start of the scheme and construction inflation running at about twice that originally allowed for;
• changes to Workplace Exposure Limits for Nitrogen Oxides and Respirable Crystalline Silica for workers involved on tunnelling works.

Since the contract was awarded construction inflation has been running at about 5% per year compared to the 2.5% which was allowed for in the scheme budget, in accordance with Treasury Guidance. The level of inflation is expected to continue at around 4.5% per year for some years to come. The scheme uses a lot of raw materials like oil, steel & copper whose prices have been volatile recently.

The changes to Workplace Exposure Limits were introduced by the Health and Safety Executive and the new limits are significantly lower than those at the time the contract was awarded. Nitrogen Oxides are emitted by diesel machinery used in the tunnel construction and Respirable Crystalline Silica is found in the dust caused by excavating the sandstone through which the tunnel passes. To comply with the new limits the contractor needs to use different machinery and provide more ventilation. This means more expensive machinery and slower rates of progress and increased costs.