MOTORISTS can expect delays on the M4 in the next few days as one of Newport’s Brynglas Tunnels looks likely to remain closed.

A contra flow system allowing traffic in both directions in the eastbound tunnel was expected to remain in place today following yesterday’s unexplained lorry explosion.

The city was brought to a standstill yesterday after the blaze tore through the westbound tunnel.

Fire crews were called to the incident at 8.33am where a lorry carrying steel was well alight, although howthe blaze started is unknown.

Motorists reported hearing several explosions as huge plumes of thick black smoke rose above the city from both entrances of the tunnel.

Remarkably no other vehicles were involved in the incident and all motorists, including the lorry driver escaped without injury.

It took 25 firefighters nearly four hours to get the fire, which damaged the inside of the tunnel and reduced the lorry to a shell, under control.

Traffic chaos followed as highways agency staff moved quickly to close the motorway fromjunctions 28 to junction 24, in both directions. Motorists were diverted onto the A48 South Distributor Road bringing traffic to a slowcrawl on all major routes throughout the city.

Tailbacks on the M4 were reported as far back as Magor in the westbound direction and junction 32 Cardiff gate the other way, while the A48 to Cardiff via Castleton was gridlocked as far back as Rumney for most of the day.

What is normally a 30 minute car journey to work from Cardiff to Newport for Charter Housing employee Rhian Woodman, 23, took more than two hours.

Welsh Government engineers arrived at the tunnels around midday to check for structural damage before a contra flow system was set up in the eastbound tunnel allowing traffic back onto the M4 late yesterday afternoon.

The blaze damaged traffic cameras and the overhead gantry controlling the variable speed limit near junction 26 and the electricity supply to the westbound tunnel was cut off, while firefighters worked.

Motorists in other parts of Gwent and beyond were also affected as parts of the A449 to Monmouth was closed to prevent people joining the motorway at the Coldra roundabout. Traffic was instead diverted through Abergavenny and Pontypool, while Newport’s Heidenheim Drive near Sainsburys was also shut.

Junction 30 of the M4 was later closed to prevent further tailbacks but all junctions reopened last night.

Investigations are ongoing into the cause of the blaze and a Welsh Government spokesman said exact details on how long the westbound tunnel would be closed for and the extent of the damage is still being accessed.

The spokesman said there remains considerable work to clear debris and conclude the structural assessment to ensure the tunnel is safe for use.