 route planned for the
deep bore tunnel would in fact only include 2.8 km. of deep bore. The
remainder of the route would be constructed by cut-and-cover in an area
where archaeological sites are more dense than on the route of the proposed
cut-and-cover tunnel (Wainwright, interview 24/2/99). The civil engineer
consulted confirms that the first 750 metres at either end of a deep bore
tunnel are usually cut and cover.
A longer tunnel following the present route of the A303.
Although the original ('green route') long tunnel was envisaged as passing
under the Avenue and Cursus, a deep bore tunnel starting further east
could follow the present route of the A303. After crossing the eastern
boundary of the World heritage site, the A303 passes through a cutting.
If the tunnel started within this cutting, it could pass further beneath
the surface of Stonebarrow Bottom, eliminating the covering embankment.
The line of the prehistoric feature, the Avenue, could then also be restored.
A four kilometre tunnel would push the start of the approach cuttings
back to the borders of the World Heritage site, but would not place them
outside the site. A longer tunnel would require above-ground ventilation
shafts (Master plan 1998: 4). The civil engineer consulted confirms that
any tunnel more than 2.5 kilometres long would require above-ground ventilators.
A four-kilometre tunnel would probably require three, each consisting
of a single-storey building. Brian Davidson suggests it would be in keeping
with a 250 year tradition to conceal such ventilators behind small tree
plantations (interview 15/3/99).
The position of the National Trust
No tunnel can be constructed without the agreement of the membership of
the National Trust. The 2.5 million members have not yet been consulted.
Land which the National Trust holds inalienably will have to be surrendered
to allow construction (Peter Fowler, interview 17/3/99). As noted above,
the Director General of the National Trust said in 1994 that the long-bore
tunnel was the only feasible alternative which met World Heritage site
Costing the heritage value of Stonehenge and the benefits
of placing the A303 in a tunnel
Stonehenge is one of 14 World Heritage sites in the UK and the 'premier
prehistoric site of Britain' (Anon 1998: 731). Its poor treatment is a
national disgrace (Tunnel Vision annexe A). The deep bore tunnel might
make good economic sense if its contribution to enhancing the heritage
value of Stonehenge could be fully costed (Stone 1998: 734). Visitors
might be discouraged if they knew part of original landscape had been
sacrificed in constructing the cut and cover tunnel (Stone n.d.: 5) while
visitor numbers might increase if it was known the site had been improved
(Maddison et al. 1998: 79).
Recent visitor levels: The exact number of people visiting
Stonehenge each year is not known, since many park on the verge of the
road and run across to the site. Recent estimates range from 700,000 to
800,000 per year (Anon 1998: 731, Maddison et al. 1998: 78, Stone n.d.:
2; Wainwright 1996: 9). One million visitors per year are expected at
the planned visitors' centre, but not all are expected to visit Stonehenge
itself, particularly in bad weather, as it will require a twenty-minute
walk to reach the site. Indeed, the site will be better protected if fewer
people visit it, and the income from visitor spending will be made at
the visitor centre (Wainwright, interview 24/2/99).
Two attempts have been made to cost the benefits of enhancing
the World Heritage site by placing the A303 in a tunnel. Both were commissioned
by English Heritage (Wainwright, interview 24/2/99).
Tunnel Vision. In 1997 the Parliamentary Office of Science
and Technology produced a report which estimated the benefits of a tunnel
in terms of the likely increase in visitors to an enhanced site. The report
took a government standard which values the citizen's non-business time
at £3 per hour. Available statistics indicated that Stonehenge was
visited by 700,000 people per year, who travelled, on average, one hour
each way and spe