UK Roads: Brynglas Tunnel

The M4 Brynglas Tunnel was opened not long after the Severn Bridge opened. There was, if memory serves, a temporary terminal at Pyllmeyric roundabout at Chepstow off junction 23 (now junction 2 of the M48) in 1966 to meet the A48. The M4 between junction 23 and temporary terminal junction 28 Tredegar Park on the A48 (via Brynglas tunnel) would have been opened in or around 1968. 

However, the ground above was plagued by subsidence problems for years, there were two houses allegedly especially badly affected and despite extensive remedial works, these were finally pulled down – possibly in 1980 – but I think later. I suppose you could say that the boring works started in about 1965 and the tunnel finished in 1980! 

BTW, insofar as I am aware the tunnel itself has never been affected by the subsidence that it caused.

Philip Lord, Essex County Council, 1^st July 04