DRIVERS have been warned about essential works taking place at Monmouth's Gibraltar Tunnels, which means some vehicles will need to use alternate routes to enter Wales.

A contraflow arrangement will be set up at the A40 Gibraltar Tunnels while maintenance and survey works take place in both the northbound and southbound tunnels.

Diversions will be in place between 8pm and 6am on Tuesday, September 17, until Wednesday, September 18.

A40 Gibraltar TunnelsA40 Gibraltar Tunnels (Image: Google)

All wide abnormal load – vehicles with a width greater than 3 metres and length up to 16.5 metres – will be requested to use the M5 and M4.

There will be advance signage on the roads to advise motorists to plan ahead.