So, it seems the Welsh Government (in their infinite wisdom:roll want to build a new motorway around Newport (there's currently a 'consultation' where all the options seem to be some form of major new road) between junctions 23a and 29. And the Welsh Government claim to be 'green'???? There seem to be two objectives, easing congestion on the M4 around Newport and providing a Brynglas tunnel diversionary route. The proposed new road options seem like complete overkill for the latter aim, given they recently built the 'Steelworks Access Road' dual carriageway which runs from M4 junction 23a to the A48. Therefore, I would suggest a Brynglas tunnel diversionary route could be created with improvements to the A48 (or a new dual-carriageway if necessary) from the point where the Steelworks Access Road joins the A48 to either junction 28 or 29 of the M4. I would imagine this would come at far lower cost than another new road which would unecessarily duplicate the 'Steelworks Access Road' for some distance. That leaves the other aim of reducing congestion. Doing so by building more road capacity will just create more traffic and more climate change. So, can public transport in general and rail in particular generate enough modal shift to solve the problem? Where does the traffic come from and why doesn't it use rail? What rail improvements would capture enough of the traffic (I know one I'd suggest, but I don't know if it'd do any good)?