HS2: the importance of evidence

Rebecca O’Neill

Large infrastructure planning projects are often met with much controversy and debate. This is partly due to the risks involved and the conflicting views amongst actors. One such project is the proposed high-speed railway to London from Birmingham, the North of England and potentially Scotland; better known as High Speed Two (HS2). After the project received an amber-red rating in May from the Major Projects Authority (MPA) annual report there is every reason for people to be concerned. An amber-red project is defined as follows:

Successful delivery of the project is in doubt, with major risks or issues apparent in a number of key areas. Urgent action is needed to ensure these are addressed, and whether resolution is feasible’.

So the questions that must be asked are what evidence supports the project and how should we analyse the debate? The evidence in favour of the project is largely based on predictive models and statistical data. One would think that after the financial crisis of 2008, people would not be so quick to base decisions on rational predictive models. Or that after the cost overruns and benefit shortfalls of HS1 (the Channel Tunnel Rail Link) supporters of HS2 would be less optimistic in their forecasts. However, advocates of the project believe that the project is both viable and necessary to tackle over-capacity issues on the West Coast Main Line.

There are a number of ways of analysing the debate. One such way is through an evidence-based policy making lens. This approach argues that once a policy problem is identified then research evidence will fill the knowledge gap thus solving the problem. For advocates of evidence-based policy making, ‘the task of the researcher is to make accurate observations about objective reality, ensuring that error and bias are eliminated by isolating variables in order to be able to identify cause-effect relationships’. These experimental methods are usually in the form of statistical analysis and they rely heavily on quantitative data. So evidence must be about ‘facts’ that tend to prove or disprove a conclusion. Evidence-based policy making has underlying positivist assumptions that it is possible to have a value-free science. It assumes that there is an objective truth ‘out there’ and if researchers adopt a certain approach then they will find the answer to the wicked issues and social problems we are facing.

If we utilise the evidence-based policy making approach then I must come to these conclusions:

  • The actors within HS2 are rational actors who have systematically collected scientific, rigorous evidence to support their claims and their decisions are rational and value-free.
  • If there is a conflict of evidence then this is either because the actors have not behaved rationally, they have allowed emotions and values to shadow their decisions or the evidence has flaws in terms of quality and methodology.
  • Those opposed to the project have an argument based on ideologies and less systematic and rigorous evidence.

However, I propose (along with many others) that the policy process is messy, that actors are rarely rational, that evidence is not necessarily ‘out there’ waiting to be found and that assuming more information will provide policy makers with the solution is wrong. The policy process is better viewed as an arena in which actors present claims and attempt to persuade their audience that these claims are true through the presentation of evidence and persuasion. The claims made by actors within the process are based on a variety of different evidence ranging from personal opinion to rigorous, scientific evidence. A good claims-maker will have mastered the art of appealing to a range of audiences, shaping and presenting their evidence in a way that best suits their audience. The concept of evidence-based policy making does not acknowledge the role of humans in this sense.

In the case of HS2, claims were made about the West Coast main line (WCML) stating that it was almost at full capacity as well as claiming that the UK needed to modernise its railway infrastructure. They did not simply claim that it was the right thing to do; rather they captured existing discourses within society such as modernisation and economic growth. The claims-making framework enables us to explain why unfounded anecdotes can easily override rigorous scientific effort and investment. It also explains why some evidence is accepted over other evidence.

For a long time supporters of the project dismissed counter-claims and evidence arguing that the NIMBYs were being selfish, that the project was for the greater good and that they were preventing much needed modernisation. However, more and more people are questioning the claims being presented by HS2 Limited and their followers.  In practice, the philosophy of ‘what works’ often takes second place to, as Russell and Greenlagh describe, ‘experiential evidence, much of which was in the form of anecdotes or generalisations based on a person’s accumulated wisdom about the topic’. Claims-making theory, therefore, provides a robust theoretical framework for examining the process of how claims are made, received, denied through counter claims, and reshaped. It also illustrates how claims and those who make them interact to formulate public policy.


Rebecca O’Neill is a doctoral student looking at the role of evidence within High Speed Two. She has an interest in the conceptualisation of evidence, evidence-based policy making, the claims-making framework and interpretive approaches to research.

2 thoughts on “HS2: the importance of evidence

  1. “Those opposed to the project have an argument based on ideologies and less systematic and rigorous evidence.”

    Where is the disparity in evidence quality between those in favour of HS2, and those opposed? Opponents of the project have led the way in seeking publication of evidence – for example, on the actual passenger numbers on individual West Coast intercity and commuter trains.

    “However, advocates of the project believe that the project is both viable and necessary to tackle over-capacity issues on the West Coast Main Line.”

    They may well do. But the evidence points to capacity issues on the West Coast Main Line being less acute than on other lines. Yet on those other lines, the proposed capacity ‘solutions’ do not involve building a new line. For example, there is no government plan to build a new line from London to Brighton.

    The vast majority of rail journeys are short distance, and take place in South East England. So one could argue that investment in HS2 is not an optimal course of action in terms of transport decongestion, or maximising general economic benefit.

  2. Thank you for your analysis of the structure of the claims making process and the rhetorical framework given by proponents of HS2. I think it is interesting how HS2 has benefited from a consensus built by different parts of the political spectrum (based on contradictory priorities such as capacity, northern regeneration, the north south divide etc) and it is this that has given it an energy to get to its current position despite the obvious lack of rationality in the proposal.
    I have been long been interested in an alternative proposal put forward by UK Ultraspeed which produced a compelling business and technical case for a maglev system featuring a single line from Glasgow to London. There is little doubt that it is technically feasible and potentially offers the benefits of High Speed Rail with less political and economic cost. However it is different and therefore was dismissed in 2007 in favour of the conventional rail – but what is interesting was the the reasons for dismissal were not really based in any compelling evidence base. The UK Ultraspeed proposal remains undismissed in terms of technology and the cost benefits were not seriously explored, except I believe for some ‘apples to oranges’ comparisons based on experience in China!.

    In a rational evidence based world it would be given more serious consideration. What would be interesting would be some kind of open competition with detailed simulation or test based on objective and well designed criteria, in a kind of head to head, just as the Victorians did when they had a tug of war with a screw propellor and a paddleship! HS2 could be compared with Maglev and with other systems, such as Elon Musk’s Hyperloop.

    Fundamentally what HS2 needs is not dismissal but fair competition – this would lead to innovation and a real agreement. I agree that evidence is not necessarily ‘out there- but in the case of HS2 is can be or already is – the real question is why the political leadership in this country refuses to acknowlege this

    I apologise – I started this reply in recognition of your analysis of the use of rhetoric to manipulate a rational debate, and end up suggesting an empirical rational test that the state is refusing to do.This is what we need our political leaders to do – to somehow divorce party and personal ambition and act above themselves. Can they do it?

    Ultimately I think that HS2 is not a modernising proposal – it is contradictory and irrational even on its own terms. Ultimately it is an exercise in nostalgia by state actors, who are unable to understand a paradigm shift in technology and the economy offered by electrification and the digital world. People will travel from city to city and city to airport, but for different reasons and in a different kind of way than in the past. I am aware that I am also ‘claims making’ but I think there is enough evidence to give substance to them.

    The UK and particularly local and regional government have a chance to change. HS2 will be a heavy burden on local cities rather than an opportunity to develop economically, as more progressive systems might do..


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