Cardiff Crossrail Phase 2

A version of this blog also appeared in Business Live/Western Mail on January 3rd 2025

You can find more details to augment those set out below in “How to build a Metro” and in my 2019 blog Cardiff Crossrail

I started 2024 with a blog about a potential Swansea Bay Metro and how the lack of devolved powers and funding will likely mean it will never happen. This year, following my “Metro and other hopes for 2025“, I am going to focus now on Cardiff!

Cardiff Crossrail Phase 2 is the key next phase of the full Cardiff Crossrail Project. The full Cardiff Crossrail can deliver equivalent benefits of a £2-3B new build 20Km rapid transit system, for perhaps just 30% of the costs given it is based in part on making much better use of the existing rail infrastructure. Building on the current TfW Core Valley Line (CVL) Metro programme and Crossrail Phase 1a (the link from Cardiff Central to the Bay Line), Cardiff Crossrail Phase 2 Figure 3 is the essential foundation for the larger Cardiff Crossrail vision and essential to “plug the gaps” in the current Metro programme in Cardiff.

The full Cardiff Crossrail Vision

The full Cardiff Crossrail to 2040 (originally set out in A Cardiff City Region Metro and The Metro Impact Study in 2013) Figure 1 is a vitally important scheme for Cardiff, the Cardiff Capital Region and Wales. It is the core project set out in Cardiff Council’s Transport White Paper, published in 2020, and has the potential to enable the largest mode shift of any in Wales, given the large population served, and better public transport connectivity to major trip generators like Cardiff Bay and Heath Hospital. It will also enable major CO2 reductions, improved air quality and multiple development and regeneration projects along its entire route, which includes some of the most economically disadvantaged communities in Wales. There are also many opportunities for bus/rail interchange to help build our integrated multi-modal public transport grid.

Given its scale, the full Cardiff Crossrail project will inevitably be built in phases, leveraging and maximising the benefits of the current investment in Metro; especially the tram-trains, whose operational capability makes possible some of the proposals below.

Figure 1 Illustration of full Cardiff Crossrail to 2040

What does the current Metro programme deliver?

Today, the South Wales Metro is just over a year from full operation with new rolling stock, faster, more frequent services and new stations. The biggest benefits of this transformation will be felt in Rhondda Cynon Taf (RCT), Caerphilly and Merthyr. In 2026 (or even into 2027? ) we will see, in most cases, a doubling of services and capacity with all stations served by at least 4tph. Pontypridd will become the hub of this new network with 4tph operating south from Merthyr, Treherbert and Aberdare and up to 12tph heading south to Cardiff in about 20-25 minutes.

The Valleys will also benefit from the completion of the £1Bn Heads of the Valleys (HoV) road and TfWs development of a fibre networks across the CVL network. With a Senedd election coming up in 2026, Welsh Government can really talk up its generational investment in economic infrastructure in the Valleys north of Cardiff.

…and what doesn’t it deliver?

However, we still have major metro gaps in Cardiff and the stark reality that about half of its stations (on the City and Coryton lines) will see no service or capacity improvements at all, and be “stuck” at 2tph. As anyone who knows about transport planning this is pretty useless in densely populated urban areas where “no one waits 30 minutes for a 15-minute trip”!

This “gap” exacerbates some transport challenges the city is facing:

High car use Vs public transport contributing to road congestion – which also impacts bus service operations, reliability and efficiency
Some key regional trip generators not effectively Metro connected – for example Heath Hospital & Roath Park – and so locking in car dependency
Consequential impact on air quality and carbon emissions
Having in some places, suboptimal bus services competing with suboptimal rail services and limited options for effective bus/rail integration
Capacity issues at Cardiff Central for SWML services

These issues are now recognised and acknowledged by Welsh Government and Transport for Wales. So, let’s place these challenges, in the context of an opportunity.

The full Cardiff Crossrail Opportunity

We have a unique opportunity in Cardiff to develop a 20Km rapid transit network, capable of carrying an additional 2000 people an hour across the city (assuming 4tph with doubled up tram-trains of 500 capacity) and into RCT and Penarth, at a fraction of the costs of a £2-3Bn new build by making much better use of the existing rail assets in the city. This is the vision for the full Cardiff Crossrail Figure 1, which some initial WG/TfW analysis suggests could deliver the largest mode shift and most economic benefits of any scheme in Wales.

Cardiff Crossrail Phase 1a

The first tentative phase of that larger Cardiff Crossrail vision to 2040 is Cardiff Crossrail Phase 1a Figure 2, between the Bay Line and Cardiff Central now committed to be delivered by 2028/9. This is the essential key stone of the entire Crossrail project.

Figure 2 Crossrail Phase 1a (from CCC/TfW consultation)

Fig A – Cardiff Crossrail Phase 1a in context of the full Cardiff Crossrail

Cardiff Crossrail Phase 2

We now need to focus effort on securing commitment to the next essential and most important phase of the larger Crossrail Vision, and which begins to unlock some of the larger city wide and regional benefits: Cardiff Crossrail Phase 2 Figure 3.

Figure 3 Illustration of Cardiff Crossrail Phase 2 to 2028/9

This is a relatively low-cost scheme as it does not require a great deal of new track; instead it focusses on three key interventions on the existing network (and maybe a fourth) plus a phased delivery of further new stations in Cardiff where we have a high local population adjacent to existing rail lines. Collectively this will enable a much greater utilisation of the existing rail asset, generate more demand and so improve the financial efficiency of Metro operations. Crossrail Phase 2 includes a number of measures:

The essential works at Cardiff West junction to enable 4tph on the City Line and a simplification of CVL service patterns. PS June 2025 – the UK Gov CSR has committed the funds to address this issue…at last!
A short passing loop on the Coryton branch to enable 4tph the Coryton Line. PS June 2025, given CSR commitment to Cardiff West, we need WG/TfW to also and in parallel, fix the Coryton Line!
The vital “Station Link” which will enable services from the west of the city and/or Penarth (if operating as tram-trains) to route down to the new Crossrail platforms planned at Central and onto the bay
Four or five more Metro rail stations at places like Ely Mill, Gabalfa, Roath Park, etc
We also include a little further electrification on the Vale of Glamorgan line to allow tram-train (we will need to order more) operation to/from Penarth and to Crossrail PS these Penarth services to the bay via “Station Link” maybe operationally easier to accommodate than from the City Line?
The tri-modes currently planned for Penarth services can instead be used to operate the new Bristol TM-Cardiff Central “Burns” services committed in the recent CSR
Crossrail Phase 1b from the Bay station to Pierhead Street

In parallel I also hope/expect the UK Government to step with funding, re the long overdue SWML upgrade and Burns stations – including Cardiff East. (PS June 2025 – the UK Gov CSR has set out funds to begin this programme!) We also need some movement on Cardiff Parkway. Cardiff council will also, I hope make progress on more bus lanes and prioritisation in the city as set out in its current consultation.

Benefits of Cardiff Crossrail Phase 2

This relatively modest package (capital estimate circa £150~200M plus some additional tram-trains) will fill the gaps in the current Metro programme and enable the delivery of multiple benefits (where the total is greater than the sum of the parts given the network benefits):

Significantly more CVL network capacity, redundancy, reliability and recoverability (especially an ability to route CVL services via the City Line to the bay avoiding an already congested Queen St station and Intersection Bridge over the SWML which will need a major renewal in the next few years)
A minimum of 4tph at all the metro stations in Cardiff using a simpler and more legible CVL service pattern – this is the minimum “turn up and go” frequency we need to begin to attract people out of their cars
Mode shift to public transport for many more trips in the city and wider region as set out in the Councils Transport White Paper; in particular makes Cardiff City centre and Bay more accessible to more people across the city and region using public transport supporting economic development and regeneration at those locations
Further Transit Oriented Development and regeneration around the stations on the network – especially housing. (See Transit Oriented Development (TOD) in the Cardiff Capital Region (CCR) #3)
As part of bus reform and franchising, overt integration of bus services with Metro rail services, so stations like Ely Mil, Birchgrove, Waungron, etc become effective rail/bus interchanges once all Metro services in the city are at least 4tph
More bus vehicle kilometres (VKm) can be allocated to parts of the city where there is no rail alternative and so help build a more efficient PT grid and coverage (See Cardiff bus station, bus networks and integration…)
Subject to further investment at Central, the opportunity to free up more platform capacity at Cardiff Central for SWML services and enhancing the benefits of the investment in Metro Central
A better balance of demand to capacity for CVL Metro services, more financially efficient operations leading to lower subsidies per passenger
The foundation for the full Cardiff Crossrail; so, the NW Corridor to RCT, Radyr/Coryton Cardiff Circle link and east across the docks to Newport rd. and an interchange with the SMWL (See Cardiff Crossrail and Future South Wales Metro, Cardiff Crossrail & Metros across Wales).
The application of additional tram-train for Penarth Servies frees up trimodes for the new “Burns” Bristol-Cardiff services – and so is a lower costs RS option for that programme when combined with Cardiff Crossrail Phase 2. PS I prefer to call the Burns services the “Metro Impact Study” services!!
PS – a shorter Penarth/Central/Bay/Caerphilly/Coryton tram-train Crossrail service could adopt more efficient staffing protocols to reduce opex for such services and minimise further subsidy requirements as set out in my “suggestions” for WG and the TfW Board

These measures, collectively, will result in a CVL network that can attract more people (I estimate 25M+ passengers per year and comparable with the Newcastle Metro which has a similar catchment population), operate more reliably and with a limited need for additional operational subsidy. The better allocation of stock/services to demand will result in a reduction in the subsidy per passenger required to operate CVL services – with room for more if we make tougher decisions re: operating procedures and staffing protocols and ultimately network designation. More importantly the measures can boost economic development and regeneration in the city. Some of my Feb 2025 suggestions for the TfW Board are relevant in this regard

This has to be the focus for the next stage of Metro development for Cardiff, the Cardiff Capital Region, Transport for Wales, Network Rail, Welsh Government, Department of Transport and UK Government out to 2028/9. Without Cardiff Crossrail Phase 2, Metro is only “half done” and the benefits of Metro Central compromised. Later this year we should see the Wales Rail Board priorities formally agreed at last in a “Wales Rail Enhancements Pipeline” to be published by UK and Welsh Governments – ideally with a long-term funding commitment as I discussed with the then Rail Minister Huw Merriman and the DfT back in 2022. Cardiff Crossrail Phase 2 should be high up on that list.

In the last few months UK Government have committed to extend HS2 to Euston at a cost likely to be well in excess of £5Bn. More starkly, the DfT/UK Gov have perhaps just £400/500M of enhancements committed to Wales but circa £80Bn of rail enhancements (Inc HS2, TRU, NPR, etc) on the conveyor belt in England to 2040; Cardiff Crossrail Phase 2 is likely to be better value for money and for just 0.25% of that cost!

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