A temporary contraflow will be introduced for the Gibraltar Tunnels from next week.
The tunnels will be down to one carriageway for two nights from next Monday between 7pm and 6am.
Traffic Wales said a contraflow agreement will be in place to carry out maintenance and survey works in both tunnels.
Drug dealer with distinctive tattoo caught red-handed
New substation to boost reliability across Monmouthshire
Bridge repairs could begin soon says Monmouth MP
Raft Race raises more than £11,000 for hospice
Budget plan proposes council tax rise and hiking parking and other charges