The Saltash Tunnel is a road tunnel on the A38

A38 road

The A38, part of which is also known as the Devon Expressway, is a major A-class trunk road in England.The road runs from Bodmin in Cornwall to Mansfield in Nottinghamshire. It is long, making it one of the longest A-roads in England. It was formerly known as the Leeds — Exeter Trunk Road,...

 at Saltash

Saltash

Saltash is a town and civil parish in Cornwall, England, United Kingdom. It has a population of 14,964. It lies in the south east of Cornwall, facing Plymouth over the River Tamar. It was in the Caradon district until March 2009 and is known as "the gateway to Cornwall". Saltash means ash tree by...

 in Cornwall

Cornwall

Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...

, UK

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 and was opened in 1988.

The central lane operates as a reversible lane

Reversible lane

A reversible lane , called a counterflow lane or contraflow lane in transport engineering nomenclature, is a lane in which traffic may travel in either direction, depending on certain conditions...

 to cope with holiday and rush hour

Rush hour

A rush hour or peak hour is a part of the day during which traffic congestion on roads and crowding on public transport is at its highest. Normally, this happens twice a day—once in the morning and once in the evening, the times during when the most people commute...

 traffic and the speed limit is 30 mph. The tunnel is used by more than 38,000 motorists per day and is 410 m long. It was designed by Mott, Hay and Anderson

Mott, Hay and Anderson

Mott, Hay and Anderson was a successful 20th century firm of consulting civil engineers based in the United Kingdom. The company traded until 1989, when it merged with Sir M. MacDonald & Partners to form Mott MacDonald.-Early years:...

, built by Balfour Beatty

Balfour Beatty

Balfour Beatty plc is a British construction, engineering, military housing, rail and investment services company. It is one of the largest construction companies in the UK, and the 15th largest in the world...

, and has a design life of at least 100 years.

Construction

During construction of the tunnel a problem was encountered with flooding due to the saturation

Aquifer

An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...

 of the surrounding rocks. The resultant flow of water was channeled through the tunnel, hidden by a decorative cladding. Within a few months this cladding had begun to crack and water entered the part of the tunnel reserved for traffic; although no structural problems were found the water staining on the cladding gave the impression of a poorly built tunnel. This was commented upon in Parliament by the local MP, Colin Breed

Colin Breed

Colin Edward Breed is a British Liberal Democrat politician. He was the Member of Parliament for South East Cornwall from 1997 until he stood down at the 2010 general election.-Early life:...

, and a £7.4 million renovation project was contracted to Skanska

Skanska

Skanska AB, is a multinational construction and development company based in Sweden, where it also is the largest construction company. The company's head office is in Solna, north of Stockholm.-History:...

to provide for a new tunnel lining and improvements to the electrical system.