A sunken motorway scheme is one of 22 alternatives to the proposed M4 relief road that is being considered by a public inquiry in Wales.
The five-month inquiry kicked off yesterday with Inspector Bill Wadrup saying that one plan includes sinking the motorway via a tunnel.
The enquiry is to look into proposals for a motorway which will relieve congestion on the M4 between Mangor and Castleton.
Time has now been programmed into the inquiry to hear the case for each alternative, the reasons why the Welsh Government rejects them and any counter-objections.
The Welsh Government’s preferred route option, the so-called ‘black route’, would be a new six-lane motorway which would run below junction 23a to junction 29 and includes a new bridge over the River Usk to the south of Newport. This is the main route the inquiry will consider. The majority of opponents to the black route favour the alternative blue route, which runs further north.
Costain, Vinci Construction Grands Projets and Taylor Woodrow with consultants Arup and Atkins, make up the design development team for the scheme, supported by environmental consultant RPS.
The inquiry has been delayed from last year after the introduction of a revised methodology to forecast traffic growth by the Department for Transport meant the Welsh Government needed more time to consider the new data.