Decisions needed now to deliver best value out of revised HS2 line

While a lot of attention has been paid to how the money due to be spent on Phase 2 of HS2 will be reallocated to projects under the banner of Network North, construction on the Phase 1 section from Old Oak Common in west London to Birmingham has continued at pace.

But even though there has been much less focus on Phase 1, cancellation of the northern section creates a number of new questions about how passenger services will be delivered on the Phase 1 route and how they will connect onto the existing network as they travel northwards. Decisions made today or those deferred could have far reaching implications for the HS2 passenger experience.

Those same decisions may also lock in what services can be delivered in the future. In addition, they may realise cost savings or significantly add to the overall bill. So, it is critically important that we take the time to properly evaluate all the options to ensure that the public get the best value out of what has been spent so far and what will eventually be invested in Phase 1.

Following the decision to cancel the majority of Phase 2, we brought together a working group of leading experts with knowledge of wider transport issues in the UK to consider how to maximise the final outcome of the remaining elements of HS2. One of the outcomes of that discussion was a decision tree to consider the various options available to maximise the value of Phase 1 and to map out what each decision might then mean both for the work programme and for services after construction. We very quickly had multiple binary decisions, each with their own merits and challenges, that mapped out the impact on passenger services and, critically, the final passenger experience.

One of the key questions was around 400m long HS2 trains moving onto the existing network north of Birmingham. To do so, you would either have to lengthen platforms or ask passengers travelling north of the West Midlands to travel only in specific carriages.

Then there is the issue of having a two-speed journey – 225mph to Birmingham and a drop to 125mph afterwards. If these issues are not addressed, what kind of passenger experience would the completed section of HS2 offer?

One option would be to rethink plans for HS2 rollingstock and use one part of the 400m trains rather than both sections and operate them in their 200m configuration.

This approach avoids the need for costly station upgrades north of Birmingham but that could mean that HS2 services to places like Manchester would actually have less seats than the current trains. There is also the question over the time to get the governance in place to enable use of a private sector development corporation to deliver the Euston terminal itself. Beyond the governance issue, it is going to take time to plan, procure and negotiate but it was good to hear transport secretary Mark Harper say at a recent Transport Select Committee meeting that the experience of developing Battersea on the Northern Line Extension is being taken into account.

However, the development corporation route raises a few concerns as the deal would apparently see the Euston approach tunnel construction undertaken by the developer. In the time taken to get that developer in place, work on Old Oak Common will have continued to a point that could create real hurdles for the launch of tunnel boring machines from there to drive the tunnels. But the best value and most technically robust option would be to build those tunnels now.

Without Euston station in place when Phase 1 does open, Old Oak Common station will certainly be the interim terminus in London for HS2. While it will be a modern station purpose built with good passenger experience in mind, there are questions about whether the Elizabeth line has capacity to cope with the onward journeys. Plus, while the Elizabeth line provides good east-west connectivity, it does not deliver the north-south connections that Euston could.

There are lots of options available today, some of which could really maximise the business case of what is currently being built. Conversely, not making decisions could jeopardise the value. It is worth reflecting that despite the challenges in getting the Elizabeth line completed, passengers now love the service with ridership higher than anticipated. The question is, what do we need to decide now to ensure passengers quickly feel the same way about HS2 when it opens? This is something that needs much more debate – and soon.

This article appeared first in New Civil Engineer magazine on 5th December 2023.