HC Deb 15 November 1985 vol 86 c329W
Mr. Rost

asked the Secretary of State for Transport if he has made any estimate of the cost of construction using the cut and cover technique of that part of the proposed Okehampton bypass which it is intended should traverse Dartmoor national park.

Mrs. Chalker

The proposed southern bypass of Okehampton does not traverse the national park; it runs along the northern edge mostly within about 50 yards of that boundary. A cut and cover tunnel would not be a practicable proposition as it would demand unacceptably deep cuttings into the escarpment and the road's proximity to the railway line at Fatherford would make a cut and cover tunnel impossible there without moving the line of the road.

A driven tunnel could be engineered, but either would be extremely expensive. On a conservative estimate a tunnel would cost about £80 million a mile or around £380 million for the 4¾-mile length along the national park. This compares with £22 million for the entire 5¼-mile bypass now planned which, of course, will be almost as well hidden from view as any tunnel.