The Strand underpass is a one-way road

tunnel A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube cons ...

in central

London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...

connecting

Waterloo Bridge Waterloo Bridge () is a road and foot traffic bridge crossing the River Thames in London, between Blackfriars Bridge and Hungerford Bridge and Golden Jubilee Bridges. Its name commemorates the victory of the British, Dutch and Prussians at t ...

to Kingsway near

Holborn Holborn ( or ) is a district in central London, which covers the south-eastern part of the London Borough of Camden and a part (St Andrew Holborn (parish), St Andrew Holborn Below the Bars) of the Wards of the City of London, Ward of Farringdon ...

. Opened in 1964, it was built within the former Kingsway tramway subway, which closed in the 1950s.

History

The underpass is built within part of the former Kingsway tramway subway, which was wide and allowed bi-directional flow because of the fixed rails and relatively narrow width of the trams. The new underpass was built by John Mowlem & Co''Mowlem 1822–1972'' – Mowlem Public Relations brochure, 1972, p. 6 and opened on 21 January 1964. It is only wide and, as a result, it is normally one-way northbound because of the side clearances required. The headroom is only due to the tunnel having to pass beneath the bridge

abutment An abutment is the substructure at the ends of a bridge span or dam supporting its superstructure. Single-span bridges have abutments at each end which provide vertical and lateral support for the span, as well as acting as retaining wall ...

by a 1:12

gradient In vector calculus, the gradient of a scalar-valued differentiable function of several variables is the vector field (or vector-valued function) \nabla f whose value at a point p is the "direction and rate of fastest increase". If the gr ...

. An electronic 'eye' alerts drivers of tall vehicles and diverts them to an 'escape route' to the left of the entrance. However, high vehicles do still try to pass through and so get stuck occasionally. Strand underpass in 2007

The underpass is a concrete box within the former tram subway, with the road surface at the original track level. At the northern end of the underpass the road rises to the surface on a new carriageway supported by metal pillars. This passes through the site of the former

Aldwych tramway station Aldwych tramway station (separate from Aldwych Underground station) was a tram stop underneath Kingsway, a road in central London, England. It was built in 1906 by the London County Council Tramways as part of the Kingsway tramway subway, jo ...

; because of the greater width requirement, 27 trees and some pavement sections were removed for it to be constructed. The tunnel was used by the 521 bus route northbound until it was withdrawn in April 2023. In 2012, the direction of traffic in the tunnel was temporarily reversed, so that it was in use by southbound traffic. This was to facilitate easier traffic flow during the 2012 Summer Olympics.

References

Tunnels in London Transport architecture in London Road tunnels in England {{London-road-stub