The Friday Blog | Why HS2 Went Off the Rails: A Former Insider Explains What Went Wrong

When HS2 was first conceived, it was intended to transform Britain's railway network.

The vision was ambitious: a high-speed line connecting London, Birmingham, Manchester and eventually Leeds, while relieving pressure on the overcrowded West Coast Main Line and creating the backbone of a modern national rail system.

Instead, the project has become synonymous with spiralling costs, delays and political controversy.

Originally estimated to cost £32bn in 2011, the latest forecasts suggest the price tag could exceed £100bn. Services that were once expected to begin running this year are now unlikely to start before the mid-2030s, while plans to extend the line to Manchester and Leeds have already been abandoned.

As someone who led the technical development and design of HS2 from its inception in 2009 until parliamentary approval of the first phase in 2017, I believe there is no single explanation for how the project reached this point. Rather, it is the result of a series of decisions, structural flaws and institutional barriers that compounded over time.

The Myth of Speed and Route Design

Much of the criticism aimed at HS2 has focused on its route and its planned top speed. These issues have often been portrayed as the primary drivers of cost escalation, but the reality is more complicated.

From the outset, the railway was designed to accommodate trains travelling at up to 225mph. That decision was informed by experience from other countries. French rail experts, for example, told us they regretted designing their earliest high-speed routes around the capabilities of trains available at the time, only to find later generations of rolling stock could travel much faster.

While trains and signalling systems can be upgraded, physical infrastructure such as curves, tunnels and alignments cannot easily be altered once built.

The routes developed for consultation were not the perfectly straight lines often portrayed by critics. Engineers carefully shaped them to minimise disruption to communities, avoid environmentally sensitive areas and navigate existing settlements. However, following public consultation, pressure from local groups and politicians resulted in significantly more tunnelling being incorporated into the plans, increasing costs by more than 30%.

Design Choices Came With Consequences

Some additional costs were the result of deliberate engineering decisions.

HS2 adopted slab track construction, a concrete-based system widely used in Germany, rather than conventional ballast track. Although more expensive to install, it offers greater durability and lower long-term maintenance costs on intensively used railways.

However, one consequence was increased noise reflection. Addressing concerns from communities along the route required additional noise mitigation measures, including more extensive barriers than originally anticipated.

These were manageable challenges. More damaging issues emerged later.

A Culture of Over-Engineering

As the project progressed, there was an increasing tendency to eliminate even the smallest risks through additional design requirements and specifications.

This "gold-plating" approach may have been well intentioned, but it inevitably drove up costs. Every extra layer of assurance, every redesign and every attempt to engineer out minor risks added complexity and expenditure.

On a project of this scale, those costs accumulate rapidly.

The Biggest Problem: Nobody Was Truly in Charge

Perhaps the most significant issue was governance.

Although HS2 became official government policy in 2012, it lacked sufficient influence within Whitehall and across the wider public sector. In practical terms, the project often struggled to assert itself when competing priorities emerged.

Local planning authorities approved developments that conflicted with the proposed route. Other government departments made decisions without fully accounting for HS2's future requirements.

In many cases, it felt as though the railway simply did not exist in the minds of decision-makers.

Even after Parliament had overwhelmingly endorsed the scheme, existing rail capacity that had been earmarked for future HS2 services was allocated elsewhere. This forced additional investment in track and signalling infrastructure that had not previously been required.

The consequences were particularly severe at Euston. Original plans relied on freeing up sufficient existing railway capacity to allow construction of the new station in a single phase. As those assumptions changed, entirely new delivery strategies had to be developed, adding years of delay and significant extra cost.

The Veto Problem

Large infrastructure projects inevitably require engagement with numerous organisations, but HS2 encountered a system in which many stakeholders had the power to delay or block progress while having little incentive to facilitate it.

Utility companies sought extensive upgrades when infrastructure needed relocating. Transport bodies attempted to link unrelated investment requirements to the project. Environmental constraints often required redesigns and additional mitigation measures.

Each individual request may have been reasonable when viewed in isolation. Collectively, they created a continuous cycle of redesign, negotiation and delay.

Unlike projects confined to a single site, HS2 stretches across hundreds of miles, bringing it into contact with dozens of local authorities, regulators, agencies and infrastructure owners.

Managing those relationships became a major challenge in itself.

A Shortage of Skills

Labour shortages have also played a significant role.

Much attention has focused on the availability of construction workers, but HS2 required expertise across a huge range of specialist disciplines long before major construction began.

Archaeologists, ecologists, surveyors, planners, legal specialists and land acquisition experts were all needed in large numbers. Competition for these skills increased costs and extended delivery times.

The stop-start nature of infrastructure investment in the UK has only made these shortages worse by discouraging long-term workforce development.

A Project Too Big for One Phase

Looking back, one of the key lessons may be that the first phase attempted too much at once.

The longer a project takes to build, the more expensive it becomes. Inflation, management costs, programme overheads and repeated redesigns all increase as schedules extend.

In 2009, we argued that the first phase only made sense if it formed part of a wider national network. That view has not changed.

Looking Beyond the First Phase

Despite the difficulties, the fundamental challenge HS2 was designed to address has not disappeared. Britain still needs additional rail capacity. Major cities still require better connectivity. Long-distance rail demand continues to grow.

The hope now is that lessons from the first phase are properly understood and applied in future infrastructure programmes.

If the line is eventually completed, its value will be maximised only if future generations build upon it. That means revisiting connections to Manchester and, ultimately, Leeds.

The tragedy of HS2 is not simply that it became expensive. It is that a project intended to reshape Britain's transport network became trapped in a system that made delivering it far harder than it needed to be.