M4 relief road: The 22 alternatives to black route
A tunnel proposal put forward as an alternative for the planned M4 relief road would cost almost £10bn, Welsh Government estimates suggest.
The Welsh Government wants to build a £1.1bn six-lane motorway south of Newport to relieve congestion on the current M4 between Magor and Castleton.
A public inquiry will look at 22 alternatives to Welsh Government's preferred 15.23 mile (24km) route.
This video shows the other options.