Hauliers have said they fear a ban on HGVs on the M48 Severn Bridge will be a "nightmare" for congestion on roads around south east Wales.
From Tuesday, vehicles over 7.5 tonnes will no longer be able to use the original crossing because the cables which support the bridge are deteriorating.
National Highways said safety was their "number one priority" and the weight restriction was to future-proof the bridge "for years to come".
But there are concerns the move will see more congestion on the Prince of Wales Bridge as well as other routes as HGV traffic has to use a 13-mile diversion back to the M4 Magor junction.
