As part of essential safety works and wider improvements to the M4, planned overnight maintenance at the Brynglas Tunnels at Newport will take place from Monday June 20.
Fel rhan o waith diogelwch a gwelliannau ehangach i’r M4, bydd gwaith cynnal a chadw dros nos ar Dwneli Brynglas yng Nghasnewydd yn dechrau ddydd Llun, 20 Mehefin.