The headlines surrounding High Speed 2 (HS2) have taken another bruising turn. Transport Secretary Heidi Alexander recently informed MPs that the line’s final bill could now hit a staggering £102.7bn, with the opening window pushed as far back as 2039.
For context, when the project was greenlit in 2011, the estimated cost was £32bn (around £49bn in today’s money) with an original opening date of 2026.
As project professionals, it is easy to look at a megaproject of this scale and assume its problems don’t apply to enterprise change initiatives. But the truth is, the failure points of a £100bn railway are exactly the same as a £1m digital transformation, data migration or target operating model redesign. They just have more zeros attached.
If we want to ensure our own projects don’t become, in the Transport Secretary’s words, “a symbol of decline,” we have to look closely at what went wrong. Here are three core project management principles HS2 compromised on – and how your business can avoid the same traps.
1. Beware the “Optimism Bias” in Scope and Costing
The delta between £32bn and £102.7bn isn’t just inflation. It is the cost of Optimism Bias – the systematic tendency for project creators to underestimate costs, timelines, and risks, while overestimating benefits.
When HS2 was conceived, it was sold on a best-case scenario. When complex realities hit, like navigating dense UK planning laws, purchasing expensive land, and digging massive tunnels under the Chilterns, the original baseline shattered.
The Avoidance Strategy: Never baseline a project on a “perfect run.” Look at similar past projects and use their actual outcomes to benchmark your budget and timeline. If historical data says a project like yours typically overruns by 20%, build that into your risk profile from day one.
2. Scope Creep and the Cost of Late-Stage De-scoping
In project delivery, changing your mind late in the game is the most expensive thing you can do. HS2 has suffered from constant political and physical re-scoping. Entire legs (Leeds and Manchester) were cancelled, yet billions had already been sunk into preparatory work. Now, to salvage budgets, speed targets are being cut from 360 km/h to 320 km/h. When you reduce the core value proposition of a project after spending the money, your return on investment (ROI) collapses. You end up paying triple for a watered-down product.
The Avoidance Strategy: Establish a rigid Change Control Board early. If a major scope change is proposed mid-flight, calculate the “Sunk Cost vs. Value to Go.” Sometimes, stopping a project entirely is cheaper than pivoting it into an expensive compromise.
3. The “Sunk Cost Fallacy” and Governance Drift
The HS2 update highlights a classic governance trap: blaming the past while dragging the future. Governments change, project sponsors move on, but the project keeps rolling forward simply because “too much has been spent to stop now.”
When project governance lacks objective, hard gates to evaluate whether a project still makes strategic sense, it enters a state of drift. The project becomes about finishing, rather than delivering value.
The Avoidance Strategy: Every major project milestone must feature a formal, objective review where the primary question isn’t “How much have we spent?” but rather “Does the remaining spend justify the remaining value?”
To prevent governance drift, introduce independent assurance – external auditors or an outsourced PMO (Project Management Office) without emotional equity in the project.
The Bottom Line for Leaders
At CI Projects, we know that successful delivery isn’t just about managing tasks; it’s about managing reality. The lesson of HS2 is a reminder that big ambitions require ruthless pragmatism.
Big engineering requires big planning – but robust project governance is what actually gets the train to the station.