Weston Hills Tunnel
|Weston Hills Tunnel|
|Location Map ( geo)|
The Weston Hills tunnel is a 200m (220yd) long twin bore cut and cover tunnel carrying the A505 under the Weston Hills. The tunnel has two "bores", each carrying one carriageway of the A505. The tunnel was built between 2003 and 2006 as a part of the A505 Baldock Bypass. Whilst the tunnel looks as if it was bored, in fact it is of cut and cover construction. The hill above the tunnel was removed during construction to enable the tunnel structures to be built in-situ. The hill was then reinstated over the tunnel and returned to agriculture.
The reason for the tunnel is to negate the visual impact upon the landscape that a large cutting would have produced (see photographs of construction). This is also why the tunnel itself is relatively short compared with the large cutting to the south of the bores themselves.
An unanticipated positive consequence of the cutting into the chalk cliffs is an increase in rare butterfly species found in the area, as it has created a steep chalk cliff habitat which has enabled population growth.