The South Wales M4 Corridor – The Perfect Testbed for A Shift to Zero Carbon Strategic Planning

The M4 is of course the only strategic route into south Wales (the two lane M50 is not a real motorway). It also has become the main focal point for employment growth with many locations only accessible by car. Cardiff and Newport have two junctions each leading to junction hopping. The M4 is only congested at peak suggesting its strategic function is stymied by local commuting; which is not what motorways are for.

With the M4 relief road stymied the Welsh Government set up the Burns commission ( South East Wales Transport Commission), led by the former Treasury Secretary, which issued a final report at the end of November.

Boris Johnson has sparked a row by saying he will

“do the things the Welsh Government has failed to do”.

The UK internal market bill recently given royal assent effectively gives the UK government the power to devolve transport and economic regeneration if they wish, meaning they could force through a project such as the M4 relief road.

The Welsh Sectrary however poo poos this.

Simon Hart said UK ministers would “much prefer” a “collaborative project” to tackle congestion around Newport and the Brynglas tunnels.

He added that while they “probably could” bypass Welsh ministers it would be “complicated” and “controversial”.

Lord Burns said in the report

“It is clear that people in South East Wales do not have good alternatives to the M4. Many people have little choice but to use the motorway, given the lack of public transport options. We believe that a competitively priced, efficient and reliable public transport network could become the first choice for many travellers.”

Lord Burns added that “even a moderate reduction” in cars on the M4 could “result in a significant improvement to the travel flow”, while the shift to public and active transport would have wider environmental and health benefits.

Now Boris has set up his own commission on Union Transport connections

In October, Network Rail chair Sir Peter Hendy was commissioned to lead an independent review into UK transport connections, which will consider the feasibility of a bridge or tunnel between Scotland and Northern Ireland.

The review will look at how to boost transport infrastructure throughout Scotland, Wales, Northern Ireland and England via road, rail and air, and across the Irish Sea.

It will examine how such links could be improved to fuel the UK’s recovery from the Covid-19 pandemic, improving connections, creating new ones and levelling up access to jobs and opportunities.

Whether Boris Johnson gets his much-loved Irish Sea bridge will grab the headlines but this report is likely to contain much more including alternatives to the scrapped M4 Relief Road, as well as suggesting improvements for rail links between Scotland and England.

New Civil Engineer

Its proposals centre on improving train services between Cardiff, Newport and Bristol by upgrading the four track South Wales Main Line, so it can be used by more trains with more flexibility.  For the first time, this would allow for local, commuting services to run frequently without disrupting express rail services.

The Commission also suggests an ambitious railway station building programme, which would add six stops between Cardiff and the River Severn. To complement existing stations at Cardiff Central, Newport and Severn Tunnel Junction, the proposed new stations would be Newport Road (Cardiff), Cardiff Parkway (St Mellons), Newport West, Newport East (Somerton), Llanwern and Magor.

The rail backbone would be supported by new rapid bus and cycle corridors across the region, especially within Newport. Taken together, over 90% of Cardiff and Newport’s population would live within a mile of a railway station or rapid bus corridor if the proposals are taken forward. Many these recommendations can be delivered through upgrades to the existing rail and road network.

As a rail guy I can’t see Henry going against the Burns commission, especially as the technical rail work has been done. What is remarkable is that the Cardiff – Bristol Severn Rail Corridor already has 4 track but doesnt function as rapid transit, and it comes through through main stations and so doesnt need any tunneling. Creating 4 track for Northern Powerhouse Rail will probably cost 20 billion. Here it could be done for 200 million.

What is frustrating is that all these options open up because there is for a the first time a well funded strategy. There have been many el cheapo reports about rapid transit is south wales over the years which ask for everything and deliver nothing. Also the Newly formed Transport for Wales for the first time is looking at modes across the board and land use transport integration. Contrast that with Highways England and the Lower Thames Crossing.

If the Welsh Government is canny they will now look at rates of return and do full feasibility studies. Spin it as ‘Severn Express’ project, delivering the kind of benefits of NPR but at a fraction of the cost. Boris would buy into it as he could use it as a means of rubbing Sturgoens nose in it.

I would suggest the sensible thing to do is run express tram trains (3 carriages) on it with high frequency.

A phase 2 of the project would be to extend tram train running along the Seven Valleys corridors – what is currently the South Wales Metro project. Tram trains would allow for on street running in Cardiff City centre and an improved link to Cardiff Bay. Imagine being able to commute from Pontyprydd to Amaon in LLanwern?

Current development plan sites along the M4 corridor should be rezoned as logistics sites only and charged ramp control should be used at peak times as a revenue source for the rail proposals.

The sensible new station locations are already major growth nodes (Llanwern) or could be, please no Cardiff Park – Marshfields instead.

This is in marked contrast to the current approach. The report

In Emerging Conclusions (July 2020), we explained our finding that land use and transport
decisions are contributing to congestion. In particular, our judgement is that a root cause of
M4 congestion is that many important origins and destinations have been located close to
the motorway without meaningful transport alternatives.


We have found prominent examples in housing estates, employment sites and retail parks. In the absence of more developed transport alternatives, the motorway has been a natural axis around which to plan developments.

While it may not always have been a conscious decision, the location of existing settlements and
topographical constraints means the available land has generally been close to the M4.

Without a change in approach, this looks set to continue. In the future, both Cardiff
and Newport are planning for physical and economic growth. The areas for development
tend to be located in an arc across the northern and western fringes of Cardiff and in the east of
Newport. These sites are relatively close to the M4, on the edges of built-up areas and often
poorly served by public transport. Other things being equal, we expect these developments to
increase use of the M4 and hence congestion.

Certain patterns of land use can support the effectiveness of the network we are
recommending, allowing a positive cycle of development and patronage to develop. For
example, increasing public transport services to a station allows a greater number of people to
access that area, which may prompt either a rise in population or employment density around
the station, creating more demand for public transport and hence building the business case
to increase services further.

By changing land uses as we develop a new public transport network, we can positively
influence these cycles. While they may take a number of years to come to fruition, the risk
of not taking action is that alternative cycles persist instead. For example, decreasing public
transport services to a station increases cardependenc e of the people who live and work
in that area, increasing demand for car travel, causing congestion, requiring either additional
roadspace for cars or prompting relocations to places further afield and hence undermining the economics of existing public transport services.

An approach to development that does not depend on cars is possible. Other successful city regions internationally and in the UK have located and designed new developments so that
they can be served mainly by public transport and active travel.
306 As cities and towns develop, they have the opportunity to increase the concentration
of development. Sustainable transport is most prominent in those places which are compact,
dense and promote a variety of land uses.


These features can be characterised as ‘Transit Oriented Development’ (TOD)…planned and projected growth. We understandthis necessarily involves more housing. However,
we believe it is possible to provide medium density developments while promoting high
quality public realm and green spaces. Indeed, we strongly believe the nature of a place is
enhanced if it allows for a greater provision of walking, cycling and public transport….

We make three land use recommendations which reflect the development opportunities
which arise from the network approach….

First, we recommend an increase in mixed use developments.

Second, we recommend employment be located within towns and city centres and not
on the outskirts close to the motorway

Third, we recommend densification around the stations and corridors of the
network…

We recommend the Strategic Development Plan should deliver the function of master planning the region, which cannot be done on an individual Local Authority basis. This master planning should identify the strategic locations most suitable for development in South East Wales. A proactive approach is necessary given the difficulty of retrofitting existing developments with transport infrastructure. A case in point is
our recommendation for a new rail station at Newport West to provide access to the large
employment sites; the options for the station and bus access is constrained by past decisions.
320 Our view is that regional planning is most effective when there is regional governance in
place. This is only partially the case in Wales.
We therefore welcome the establishment of statutory Corporate Joint Committees (CJCs)
to provide for coordination across Local Authorities.

What we have in South Wales therefore is the ONLY urban region in the UK to have a comprehensive intermodal transport and land use plan in genesis which could be backed by a statutory strategic plan. It is the only urban region with a potential pathway to zero carbon growth. Wales puts English Planning, and Boris, to shame.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s