The Brynglas tunnel on the M4 in Newport (Image: Google Streetview)
The M4 Brynglas Tunnel will be closed overnight between September 24th-25th for an exercise carried out by South Wales Fire and Rescue Service.
The exercise which will be carried out from 8pm and 6am on these dates involves a large emergency service presents in this area.
A spokesperson for South Wales Fire and Rescue Service said: “Artificial smoke is going to be used in the tunnel and public should not be concerned if you see smoke in the tunnel on this evening.
"We apologise for any disruption that this may cause.”
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here