Regulation and adventure activities

On 9 June 2012 John Wiley & Sons published in EarlyView format our paper (by Laurence Ball-King, John Watt and David Ball) describing the regulation of adventure sports over the last two decades since the Lyme Bay accident in 1993. In particular, the paper traces the history of the Adventure Activities Licensing Authority (AALA) which was set up post-Lyme Bay in response to the concern which that event raised, and which now faces abolition as a result of recommendations by Lord Young’s inquiry into the conduct of health and safety. Although we find Lord Young’s recommendations timely and generally appropriate, the paper describes why we disagree in respect of AALA’s proposed abolition.

Far from being abolished, we think that AALA deserves commendation for its work and furthermore that it provides a model for other specialist sectors. The latter is because we believe that safety in adventure activities lies first and foremost in the skills, experience and competence of adventure leaders who are immersed in the activities, and not within the general health and safety community and its protocols which originate from factories. While generalist H&S practitioners may well be able to handle workplace hazards, they are not necessarily knowledgeable about the challenges of the wild. AALA inspectors, currently, are all highly experienced in their respective domains, and this is probably why, as the paper reveals, they are so well respected by those they oversee.

Copies of the article may be purchased from Wiley’s online library via the following URL:

DOI: 10.1111/j.1539-6924.2012.01850.x

Or you may request a reprint from David Ball. These should be available later this autumn.

Barbican Conference on Health & Safety Reform

Public Service Events ran a one day conference entitled ‘Health and Safety Reform – reducing the burden of red tape,’ sponsored by ARCO at the Barbican on 26 April 2012. The conference was chaired by David Ball and had an impressive line-up of speakers including Andrew Miller MP (member of Löfstedt review panel), Judith Hackitt (Chair of HSE), Luise Vassie (Policy Director, IOSH), Thomas Martin (joint-MD, ARCO) and Lynda Armstrong (Chair of Trustees, BSC). In the afternoon session panel members Stephen Williams (Director of Operation Strategy and 2012 Olympic Games, HSE), Roger Bibbings (RoSPA) and Gerard Forlin QC (Cornerstone Barristers) led the debate.

Messages to emerge included strong support for the Löfstedt review findings, notably that the underlying legislation was sound but that its interpretation was sometimes problematic and could depart from good sense and proportionality. In the words of Andrew Miller, the regime was overly complex with too much emphasis on paperwork. What was to be done? HSE’s contribution to the ambitious reform programme recommended by the Löfsted review included a comprehensive review of guidance with the aim of simplification while maintaining standards. In addition the ‘Myth Buster Panel’ had been set up, chaired by Judith Hackitt herself, and had already received its first batch of over twenty myths for scrutiny. One newly-emerged myth was summarily dealt with on the spot, namely someone’s proposal on safety grounds that holly trees be removed from school environments because of the (mild) toxicity of their berries. Judith’s response was an unreserved negative!

So the pervasive message was for a risk-based and proportionate approach to safety. But how to do this? As Luise Vassie described, what is needed is scientific evidence of the magnitude of risks in order to inform priorities, and secondly to check the effectiveness of H&S interventions.

From a personal perspective the overall drift of the conference was encouraging. The need to retain the concept of ‘reasonableness’ and ‘reasonable practicability,’ the need to prioritise on the ‘real’ risks (however defined), and the need to simplify perceived administrative demands including paperwork trails and tick-boxes which were more to do with secondary (liability) risk management than the primary focus which is safety and health. However, the task is not trivial. It requires a deeper understanding of many things which are seldom discussed or alluded to in the practicing safety world, including the nature and utility of evidence, the meaning of practicability, the behaviours of people, and the role of values in decision making. Many of these things have of course been intensively analysed in academia, but it has long been the case that the flow of academic thinking into the ‘real’ world has been erratic and sluggish.

 

The risks of long distance running

This year’s London marathon saw the tragic death of Claire Squires. Subsequent media stories revealed that Claire’s was the eleventh such death since the event began in 1981. From this one can (in a sense) gauge the relative riskiness of marathon and long distance running as a sport. From 1981 until 2012 there have been about 850,000 competitors. Taking 4 hours as a rough race time means that competitors have collectively spent around 3.4 million hours on the course. A sometimes used risk statistic for comparative purposes is the death rate per 100 million hours of an activity, known as the FAR (Fatal Accident Rate). From this:

FAR for London marathon ≈ (100/3.4) x 11 ≈ 320 fatalities per 100 million hours

Budapest marathon 2011

How does this compare with other sports and other activities? Back in 1998 I made a study of fatal and non-fatal accident rates for a range of sports ranging from mountaineering to badminton (J. Sports, Exercise and Injury, 1998; 4:3-9). At that time the data showed the most dangerous sport was that categorised as ‘air sports’ which included aerobatics, gliding, hang-gliding, micro-lights, paragliding etc, and which had a FAR in the region of 200. Mountaineering was next highest coming in the range of 30-60, but has since been displaced into third place by caving which comes in at about 160. Water-related sports such as swimming, boating and fishing all have FARs of around 10 to 20, and horse riding comes in at 10. Sports such as rugby, soccer, hockey, cricket and badminton lie in or close to the range of 1 to 3.

From this (see histogram) it can be seen that marathon running is at the high risk end of the spectrum in terms of the FAR yardstick when compared with other sports. This is also true if compared even with industries operating in challenging environments, such as offshore oil and gas, where the FAR as reported by the International Association of Oil and Gas Producers is in the range of 5 to 10.

More generally, within the UK, occupational fatality rates can be estimated from HSE statistics. The average FAR for all workers is around 15, rising to around 70 in construction and 240 in agriculture. Likewise, Department for Transport statistics report FARs for various modes of travel: car 9.8; motorcycle 430; pedal cycle 38; pedestrian 15; bus or coach 0.63; rail 1.5.

So if marathon running is so risky why do it? The answer is that participation brings huge rewards in terms of physical fitness and health, psychological benefits, and social ones too. Even businesses benefit. But the debate over the relative merits and demerits of participation in these kinds of relatively extreme pursuits has been with us for thousands of years. When the London marathon was first proposed by Chris Brasher and John Disley in the 1970s there were objections, for example, that entrance should at least be restricted to club athletes. And during the earlier 1967 Boston marathon a race official attempted to physically eject Kathrine Switzer from the supposedly all-male event on the grounds that “Anything long like 800m, or even longer, God forbid, was considered dangerous ………” for women.

Times, and views, have clearly changed, and to some extent this has been unavoidable given the accumulating evidence of the health benefits of sport. Thus, in the nineteenth century, the view of Reverend Charles Wadsworth, with reference to the Oxford and Cambridge boat race, that ‘no man in a racing boat could expect to live to the age of thirty,’ was gradually proven wrong by epidemiological research which showed life expectation to be greater for rowers than non-rowers by several years.

For a concise and enthralling account of the history of beliefs surrounding the benefits or otherwise of physical activity, see Domhnall MacAuley’s ‘A history of physical activity, health and medicine’.

The debate, of course, continues. But it does illustrate the importance of collecting evidence and not being overly reliant upon subjective opinion and prior beliefs.

Public Safety and Risk Assessment book: Available now

Public Safety and Risk Assessment: New book published in September 2011 by EARTHSCAN/Routledge.

This book is the outcome of over 30 years of involvement with the public, public sector bodies, regulators and the academic community. It explains swathes of academic research from numerous disciplines including risk, economics, psychology, philosophy and decision making and applies them simply and coherently to the intensely practical matters faced by public and private sector bodies responsible for the provision of public space and activities. A second crucial input is first-hand experience of the law pertaining to safety based on numerous cases undertaken as an expert witness.

The purpose of the book is to explain the basics of risk and safety from first principles and take you to a deep understanding of what risk assessment is about, and what it can and cannot deliver. The authors believe that if you do not understand the underlying philosophy of public safety and risk you will forever be vulnerable to competing ideologies which will occupy the slack space bequeathed to them.

Prior to publication the book was reviewed by Sir Chris Bonington, Lord Hoffmann, and Professor John D. Graham. We are immensely grateful for their support. This is what they said:

“So many worthwhile activities are banned or rejected in the name of Health and Safety. Everyone should read this book to see that very often these bans are not justified.” – Sir Chris Bonington

“This book strips away the mysticism and jargon from health and safety, subjecting it to rational analysis. It shows that safety precautions always have to be paid for, in money and lost opportunities, and involves choices which cannot be left to experts but should concern all members of a democratic society.” – Lord Hoffmann

“Safety is important, but it is not paramount. This book exposes the myths and reinstates the choices we have in determining our lives. Trade-offs are unavoidable. We need to make them with as much care and understanding as we can muster. Read how.” – Professor John D. Graham, Dean, School of Public and Environmental Affairs, Indiana University

Since publication Professor Ragnar Löfstedt of King’s College London and author of ‘Reclaiming health and safety for all’ has said in that selfsame document (page 93):

“Ball and Ball-King’s recent book helpfully summarises the key issues surrounding the risk assessment process in the context of public safety.” – Professor Ragnar Löfstedt

Click here to order the book on Amazon.

About the Authors

David Ball is Professor of Risk Management and Director of the Centre for Decision Analysis & Risk Management at Middlesex University, UK. Previously he was Director of the Centre for Environmental and Risk Management at the University of East Anglia, and before that worked as a scientist in local and central government and the private sector in Britain and the USA. He is a regular consultant to government departments and regulators as well as international agencies. Laurence Ball-King has a Masters degree in risk management and a BA in economics and politics. He has worked in credit risk management within financial services and on a variety of non-financial risks including adventure activities and public safety more generally.

The Future of Risk Assessment?

Risk assessment is used to hugely-beneficial effect in many industries, ranging from off-shore oil and gas to nuclear and transportation. It is also used to plan for health epidemics, food safety and flooding. Generally the methods deployed are highly sophisticated, science-based and provide useful information for decision makers.

In recent years risk assessment has also been applied to public space and public activities, often using, by necessity, much simpler protocols such as HSE’s ‘Five steps to risk assessment’ (http://www.hse.gov.uk/pubns/indg163.pdf), or devices known as risk matrices of the type shown below which may range from 2×2 to even 10×10 cells.

These matrices, and the way they are used, are a source of worry for some eminent risk practitioners. For one thing they are usually qualitative in that there are no numerical values on either axis and both risk and consequence are subjectively-defined. What, for instance, does it mean to say something has a ‘medium’ likelihood? And in the case of public space is it the likelihood of something happening to one individual member of the public on a single visit, or on multiple visits over a year, or is it the likelihood that any member of the public might come to grief during, say, the next month? There are numerous possibilities but most matrices seem to leave this question unanswered despite having massive implications for their meaning.

Another technical anxiety is that users quite often number the cells along each axis from, say, one to three in the case of the matrix shown, and then multiply them together to generate a score for each cell. In this way the top right cell in the matrix shown would score 9, and the bottom left 1. This is troubling for several reasons. For one thing the axes are qualitative and labelling them from 1 to 3 produces ordinal numbers only (as in first, second, third etc), and not cardinal numbers. It never has made sense to multiply ordinal numbers together.

Another matter is that when numbers are multiplied, however ill-advisedly, they are sometimes said to be used as a means of prioritising and the aim of many risk assessors appears to be to shift hazards falling in the red-coloured boxes to the green ones. The requirement under the law, however, and which is deeply rational, is that control measures should be implemented if they are reasonably practicable. This is a much more sophisticated concept and is not replaceable by fiddling with coloured squares on grids. It could mean that hazards in higher-scoring boxes should not be subject to further control measures because there are none which are reasonably practicable.

An altogether different issue comes up when considering the risk assessment of public space and public activities, and this relates to the reason for their provision which is, obviously, their benefits. Public facilities, such as city squares, tree-lined streets, ponds and fountains, riverside walks, parks, playgrounds, forests, church yards, sites of cultural heritage, national parks, village fêtes, carnivals and sports of whatever kind produce benefits of all kinds ranging from health (physical, emotional and social) to intellectual stimulation, beauty and tranquillity. The problem is that these benefits get no mention in standard risk assessment protocols. It is as if the decision about whether, say, a public activity should be permitted or curtailed could be made purely by thinking about its inherent dangers and without any need to consider the benefits of the activity. This would be an irrational decision process. There is almost always some sort of trade-off between control measures and benefits when dealing with public places and public activities and it is essential that this be recognised, not ignored.

In effect, what has to be done is to weigh the benefits of, say, an unspoilt riverside walk and its risks, and make a decision on whether it should be left as it is or modified. This approach, of weighing risks and benefits, is what is increasingly being referred to as risk-benefit assessment (RBA). If you try to make this decision without thinking about either one of these commodities, the risks or the benefits, I for one could not conceive what was going on in the risk assessor’s head. But I suspect these for me unfathomable thought processes are quite common given that standard risk assessment protocols only refer to one side of this equation, leaving it open to ignore or forget the other.

Collectively these issues suggest that risk assessment as used in public life may require radical surgery.

The Löfstedt review of 2011

From our perspective this report by Ragnar Löfstedt is both immensely welcome and dramatically  important. As was said in our evidence (by myself and Laurence Ball-King) to his Review Panel, the problems being experienced in relation to the safety of the public and the impact of safety measures on public life were not in our view attributable to our legislation (primarily the Health and Safety at Work etc Act 1974 (HSWA), and the Occupiers’ Liability Acts (OLA)), but rather to their misinterpretation. We went so far as to say in our evidence that the underlying philosophy of these Acts was even something to die for. So we are delighted that Löfstedt has drawn the same conclusion.

Why is the legislation so important? Because, as explained in our book, the UK philosophy is not about eliminating risk but essentially about doing what is reasonable, and what, we say, could be more reasonable than that?! The implication of this is that if Tom, Dick or Harry comes up with some ridiculously expensive or inordinately troublesome safety measure, you are not required by law to implement it because it would not be reasonable. So a good question to ask if you are presented with a proposition which has a whiff of over-the-topness about it, is to see the evidence that it is reasonably practicable (this should contain evidence on how effective it will be in reducing risk as well as information on costs and difficulty of implementation and any unintended consequences which the proposed intervention might have).

Also of monumental significance is Löfstedt’s total support for evidence-based health and safety measures, and for proportionality. Although both of these are obvious requirements for any rational approach to anything at all, there has been a feeling that the UK has been drifting towards a philosophy of hazard-based thinking, as opposed to the kind of risk-based thinking inferred by the HSWA.

The essential difference between hazard-based and risk-based thinking can be illustrated by a simple example. The picture below shows a traditional canal-side lock. These are used by the public for recreational purposes. They clearly expose users and casual  walkers to a number of hazards, in this case of unfenced drops and serious injury or drowning. From a strict hazard-based perspective you would be required to do something about this, maybe to put up railings or warnings or both, or even ban access. From a risk-based perspective, however, you might be able to leave it as it is if the risk of falling off can be shown to be very low, and/or the benefit of retaining the historical authenticity of the unmodified lock outweighs the risk of harm.

In fact, we think the Löfstedt report and our book tread a remarkably similar path. The main difference is that Löfstedt’s remit was primarily the effects of H&S activities on business, whereas our emphasis is upon the effects of H&S upon the provision of public space and public activities. The stories, though, are remarkably close.

The Manchester Hole Case

This involved the tragic death by drowning of a young school boy while on an adventure holiday in Yorkshire. The school party was exploring an underground cave in Nidderdale known as Manchester Hole when the cave experienced an highly unusual flooding event. The case was brought by the Health and Safety Executive who sought to prosecute North Yorkshire County Council who ran the outdoor centre. I was involved as one of several expert witnesses. The case was in court for six weeks, with ultimately the HSE losing, much to its chagrin since it seemed to challenge some of its fundamental beliefs.

A fuller account of the case can be found in Horizons volume 51 published by the Outdoor Learning Institute in December 2010 (http://www.outdoor-learning.org/Default.aspx?tabid=137), but the main issues raised in the case from my perspective as a risk professional were:

  • Should young people be deliberately exposed to risk?

HSE’s published position on this was decidedly ambiguous. According to its 1999 publication ‘Adventure activities centres: five steps to risk assessment’:

“Adventure activities aim to allow young people to develop by meeting challenges they do not necessarily face every day and to experience a sense of achievement in overcoming them. Some degree of risk is unavoidable if the sense of adventure and excitement is to be achieved. However, it is important to remember that adventure activities should only create a sense of adventure and excitement and not cause harm.”

This statement presents a field day for policy analysts, for on the one hand it implies that young people need to meet real challenges and in so doing some risk is inevitable, but then informs that adventure should be fake (only sensed) and  not cause harm (HSE’s emphasis). Apart from its obvious inconsistencies, this contrasts sharply with HSE’s previous support of the Play Safety Forum’s policy statement which says quite simply that “Children need and want to take risks…”.

  • Should risk be negligible?

The Prosecution argued that an acceptable level of risk of serious injury or death is that it should be “negligible.” Since the HSWA requires an employer to ‘ensure’ the health and safety of employees etc, so, prima facie, if an accident occurs s/he has failed. The burden then falls upon the employer to prove that they had done everything which was reasonably practicable to ensure health and safety. The HSE alleged that because an accident had happened this proved that all reasonable measures had not been taken and NYCC had to prove otherwise, which is a curiously circuitous argument for an agency which purports to have a risk-based philosophy.

Another issue of considerable interest was whether the concept of reasonable practicability should encompass consideration of the benefits of such activities. In a civil case it likely would, but this was a criminal case where the answer was less clear cut. However, Justice Wilkie, in directing the jury, explicitly identified as a material consideration ‘the benefits of conducting the activity,’ just as Lord Reid had done in a much earlier civil case.

  • Should adventure activities be managed like factories?

Oral evidence by the HSE in court was in part along the lines that health and safety systems should be designed, implemented and managed in a local authority environment in exactly the same way as in any other organisation, and frequent reference was made to one of HSE’s best-selling texts, known as ‘Successful health and safety management’ or ‘HSG65’, described on HSE’s website as an “over-arching guide on the essential philosophy of good health and safety.” HSG65 is, however, primarily written for industry, not public life, though it could be concluded from this case that HSE sees no difference. But there are differences. Local authorities are providing and managing public services for their public benefits. HSG65 was written in a benefits vacuum where such things are barely acknowledged if at all. This might conceivably be alright in an industrial environment – you wouldn’t expect factory employees to have to walk along a plank to get to the canteen, or office workers to abseil to the toilet, but in public life pitting yourself against these challenges can have benefits.

  • Have you got the right management system?

Another aspect of the HSE’s case against NYCC was targeted on alleged deficiencies of NYCC’s management system. To this end HSG65 was also frequently cited. The fact is, though, that HSG65 is an advisory document, the advice given is based on some unknown person’s opinion, the evidence-base that it is cost-effective is unidentified, and there is no legal requirement to abide by that opinion. It was not at all obvious that the kind of management system described therein was suitable for an education authority or a county council.

  • What and who make adventure activities as safe as they are?

Much time was allocated in court to arguments about the technicalities of risk assessment and who should be involved in performing this required task.

On the technical side, the prosecution’s witnesses described the essential intricacies and interlinking of generic, site-specific, and dynamic risk assessment, which, it was said, comprised a ‘three-legged stool.’ The intended inference was that all three legs had to be equally robust to avoid catastrophic failure, but there was also an impression created that this stool was the rock upon which the safety of adventure activities rested. From a personal point of view, and as I said in court, if my children were going on an adventure activity, I should not want to rely upon such a device. Far more important would be the skill, knowledge and competence of the team leaders!

With respect to who should be doing the risk assessments, HSE’s position was that professional health and safety people employed in NYCC’s headquarters should have had a greater role in compiling the adventure activity risk assessments, whereas defence witnesses, from around the country, poured varying levels of scorn upon this proposition.

The research on expertise, with which I have become familiar in recent years, has led me to believe that there are different kinds of expertise, some of which are appropriate for certain tasks, but not for others. At the bottom of the heap is ‘beer mat knowledge’ – the sort of wisdom you gain from reading about bird flu on the back of a beer mat! In sharp contrast, interactional expertise is what you get from, say, years of participation in canoeing. The implication here is that unless there is strong evidence that anyone on NYCC’s central health and safety team had maximal ‘interactional expertise’ as in potholing experience – through years actually potholing themselves or through years and years actually discoursing with cavers about technical matters – then the only deep expertise about the dangers and so forth would have lain with the adventure leaders themselves. This position accorded with the views of the adventure leaders who gave evidence in court.

Risk-benefit assessment

The move to get risk-benefit assessment recognised as a suitable and sufficient form of risk assessment is gathering momentum but still has hurdles to overcome. It seems that some agencies do not want to concede that the benefits of public space and activities should be a primary consideration in determining how safety from injury decisions should be made. This may be because this would result in a transfer of power because, to make balancing decisions, you would need to know about both the risks and the benefits of some place or activity and traditional H&S exponents may know little or nothing about benefits.

The case for RBA was strongly put in 2008 by Play England and the government in its ‘Managing risk in play provision – implementation guide’ (http://www.playengland.org.uk/resources/managing-risk-in-play-provision-implementation-guide.aspx). The case has more recently been expressed by the National Tree Safety Group in its ‘Common sense risk management of trees’ published by the Forestry Commission (http://www.forestry.gov.uk/pdf/FCMS024.pdf/$FILE/FCMS024.pdf), as well as by the long-standing Visitor Safety in the Countryside Group (http://vscg.co.uk/). Other organisations with strong interests include the Association of Heads of Outdoor Education Centres and the English Outdoor Council.

Overall, there is a widespread desire to get the benefits of public life back on the agenda of health and safety. Paradoxically, one of these benefits is health. But as the Trades Union Congress has put it, “Sadly we have a society that seems to see preventing injury as being more important than preventing illness.”

Some legal questions

Three questions come to mind right now. These are:

a) According to the most widely used criminal law definition of reasonable practicability a responsible party should always err on the side of safety according to the principle known as ‘gross disproportion’. The question is whether or not this continues to be logical either in general, or in the context of public activities specifically.

b) Whether the requirements set by the law in terms of safety should be seen as a minimum requirement.

c) Whether the law is supportive of the use of risk-benefit assessment.

In response to a) the Löfstedt report provides a much-to-be-welcomed blast of intellect and fresh air because of its emphasis upon a return to risk-based decision making (as opposed to hazard identification and remediation), the use of scientific evidence, and proportionality. Nonetheless, there remain serious hurdles to overcome and his continuing commitment to taking this forward is to be welcomed.

One hurdle is the oft-touted formula “the disproportion must always be gross” which implies a requirement to err on the side of safety to a degree which is “gross.” This position is given added emphasis by HSE in its ‘Principles and guidelines’ document to assist its own officers in which it says “but the disproportion must always be gross,” itself an apparent reference to situations in which risks may already be small. How, though, is it possible to square gross disproportion in low risk situations with Löfstedt’s proportionality?

The origin of the “the disproportion must always be gross” formula is Lord Asquith’s summing up of the 1949 Edwards v National Coal Board case.  However, there are reasons why this might now be challenged both in general and in the particular case of public space. The ‘in general’ argument is to do with the way in which safety has been valued by society. Back in the 1940s the traditional method used by government agencies was simply to do with the value of the lost earnings of an hypothetical deceased person. This came up with rather niggardly valuations of safety and it may well be that the courts were aware of this in their deliberations, so adding a weighting factor under the banner of ‘gross disproportion.’ Come the 1980s, however, the method of arriving at these valuations was switched by the Department of Transport (others followed their lead) to what is known as ‘Willingness-to-pay” (WTP). WTP methods give much higher valuations, currently in the region of £1.5 million per life saved, being based on what consumers are prepared to pay for reducing their own risks. It can be argued that applying a ‘gross disproportion’ weighting to consumers’ own valuations would be tantamount to giving consumers something they have not asked for and do not want!

As for the specific context of public space, the argument has a second thread. This is that if it is accepted that decisions about what to allow in public space require a balancing judgement to be made about the benefits and the risks of that space, then to subsequently apply gross disproportion would be equivalent to loading one scale pan in favour of the other. Why?

In response to b), it is sometimes said and written that the requirements of the law with respect to safety should be seen as a minimum requirement. Prima facie, this is a morally sustainable argument and hard to challenge. But how valid is it?

The legal requirement under the HSWA is to implement safety measures which are reasonably practicable. This implies consideration of the effectiveness of safety measures in reducing risk versus the cost, time and difficulty of applying those measures. If the risk reduction benefit outweighs the latter, the measure must be implemented, and if not, it is not necessary to do so, though safety advocates might still want to go ahead and implement. However, from the position of a neutral bystander, say the proverbial ‘man on the Clapham omnibus,’ going beyond the point of rational decision making as implied by reasonable practicability is equivalent to saying that the views of the man on that bus should be ignored.

The fundamental issue is, of course, that if an agency providing some public good decides it wants to gold-plate its safety measures, then the related costs are going to have to be picked up somewhere and that will ultimately mean the taxpayer. So the quest for higher levels of safety than those reasonably conceived is itself morally questionable. Those resources spent on one thing could have been spent on something else which is possibly valued more highly.

As for c), the answer is that Civil Law has for a long time recognised four factors in determining whether a duty holder has done all that is reasonable in taking care. The factors are the prior level of risk, the severity of the possible consequence, the practicability of control measures and the social utility of the activity. The latter is of special interest in the context of public space and activities because social utility is why they exist. So in Civil Law the use of some kind of intellectual weighing of the benefits of space versus the risks would seem to be an accepted part of the process. However, in criminal law, under the HSWA, it is less clear. Lord Asquith’s 1949 definition of reasonable practicability identified the first three of the above factors but not the fourth. But maybe he didn’t need to because the case he was thinking about was the death of a miner in a coal mine where social utility was not an issue. So perhaps the position is best summarised as one of uncertainty. The courts have not had sufficient criminal cases to work on in which this dimension was relevant (but see The Manchester Hole case).