Driverless cars and the sacred cow problem

The promoters of driverless cars have demonstrated remarkable progress in their ability to program their vehicles to respond with extreme deference to pedestrians, cyclists, and cars with human drivers. Such programming confers sacred cow status on all road users not in self-driving vehicles. The developers of autonomous vehicles acknowledge the need for new road safety rules to accommodate these revolutionary vehicles on public highways. But would-be regulators have yet to propose a set of rules that would allow these sacred cows to move about freely in dense urban areas without creating a state of deferential paralysis for those in autonomous vehicles.

Full essay here (pdf)


Risk and Culture

Risk, most dictionaries agree, involves exposure to the possibility of loss or injury. Perceptions of this possibility are embedded in culture and vary enormously over space and time. One frequently encounters the contention that it is important to distinguish between “real”, “actual”, “objective” risks and those that are merely “perceived”. But all risk is perceived. Risk is a word that refers to the future, and the future exists only in the imagination. And the imagination is a product of culture.

Opening paragraph of Chapter 7 of  Routledge Handbook of Risk Studies – click here for the complete chapter



Environmental groups’ failure over HS2

Letter in Telegraph, 17 April2016

Environmental groups’ failure over HS2

SIR – It is now very clear indeed that the hugely expensive HS2 project is fundamentally flawed; yet it continues to make progress towards delivery in spite of compelling evidence justifying its cancellation.

Its passage has been assisted by two important factors that are as problematic as the project itself. The first is the failure of both governmental and non-governmental supporters to change direction on the basis of evidence. The second is the dramatic transformation of so-called environmental groups.

The Campaign for Better Transport, Friends of the Earth, the Campaign to Protect Rural England and Greenpeace have assisted this extremely environmentally damaging project at every stage.

These groups have betrayed their members as the project will, without question, add to greenhouse gas emissions, seriously damage the countryside, destroy woodland and generate levels of noise greater than those set in World Health Organisation community noise standards.

This marks a serious decline in the legitimacy of these environmental groups. It can be seen as a huge loss in a democracy constantly struggling with the excesses of government policies that emphasise the importance of the environment but in practice contribute to its degradation.

The environmental movement has embraced the old maxim, “if you can’t beat them, join them” – and we are all the losers.

John Whitelegg

[former Board member of Transport 2000 – now the Campaign for Better Transport]

John Adams

Emeritus Professor, University College London [and member of the original board of directors of FoE]

Mayer Hillman

Senior Fellow Emeritus, Policy Studies Institute

Stephen Plowden

[independent transport planner]


Cycling and Safety: change must take root in people’s minds


Last March I took part in a conference devoted to the promotion of cycling in Madrid. My presentation, in essay form, has now been published by World Transport: Policy and Practice. Herewith the abstract –

This essay is a response to an invitation to provide an overview of the current state of cycling in Britain, and more specifically London, for a conference in Madrid – a city, like London, striving to promote more cycling. The essay focuses on the importance of both the volume of motorised traffic and perceptions of safety as determinants, over time, of the volume of cycling. It notes the dramatic decline (over 95%) since 1950 in the road accident fatality rate in Britain as cyclists, pedestrians and motorists competed for the right to the use of limited road space and how, in selected areas of London, cyclists are in the process of regaining their right to the road.

And here is Figure 7 from the essay:

graph for blog

From 1950 to 1973 (the year of the energy crisis) the number of kilometres cycled in Britain plummeted – by about 80%. Over the same period the fatal risk of cycling, per kilometre, increased dramatically. The enormous increase in motoring was, physically, driving cyclists off the road. This displacement was officially sanctioned by what became known as the “predict and provide” policy underpinning transport planning. Forecasters were employed to predict future levels of car ownership and car use, and official policy was to provide sufficient road space to accommodate the forecasts. At public inquiries into road-building plans the problems of cyclists and pedestrians did not feature.

Their problems are only now beginning to be acknowledged as issues deserving of consideration alongside those of motorists stuck in traffic jams. Change does appear to be taking root in people’s minds.

The published paper can be found here (starting on page 10) –


The Driverless Car Revolution – Amazon Review

Driverless Car Revolution: buy mobility not metal

by Rutt Bridges

Review for **** 25 June, 2015

Highly recommended, but …

Mobility Not Metal is an impressively clear and comprehensive account of the potential of the driverless car revolution – with a significant omission that we will come to shortly. It provides an intelligible description of both the technology on which it depends, and the extraordinary pace of its development. The essence of the mobility vision it presents is a world transported by Uber without the drivers. It also presents convincing evidence that it will be possible for this technology to operate safely for all road users, both in and outside cars.

Bridges is clear that driverless cars will be a massively disruptive technology, and identifies the potential winners and losers in the revolution that he forecasts. Per mile travelled it will be hugely cheaper, safer and more efficient for all travellers, but especially for those denied a driving licence because of age, disability or disqualification. The potential losers include the motor manufacturing industry (far fewer cars will be needed), motor mechanics (the new “Autos” will be much more reliable and less expensive to maintain) and an army of drivers (from those driving taxis and delivery vans to pizza delivery boys on bicycles). He is clear that the gains will greatly exceed the losses – driverless cars “will have a profoundly positive influence on all of us and our planet as well” – and that the winners will prevail – Chapter 1 is entitled “How your world will [not might] change.”

He argues his case with the help of a number of American vignettes: “For simplicity’s sake, we’ll focus just on mobility services in the U.S., provided to city and suburban markets by electric vehicles.” More specifically his demonstration of the economic advantages of driverless cars is based on their potential use in Denver: “The City and County of Denver will be the theoretical test market for the Mobility economic model.” And herein lies a problem.

Bridges’ vision of the future of driverless cars is global – he speaks of its impact on “our planet” – and he envisages its principal market being “densely populated metro areas” everywhere. But by global standards the city and county of Denver are not densely populated. 82% of its commuters currently travel by car, truck, or van, mostly from sprawling suburbs. The other favourite demonstration laboratory for driverless cars is Mountain View California also, by global urban standards an area of extremely low settlement density. How, one might ask, would the self-driving car cope in a truly densely populated metro area such as London with a population density more than 150 times that of Mountain View?

This question is not addressed. Truly densely populated urban areas have dense pedestrian traffic and, increasingly, dense cycling traffic. And, after many decades of neglect, it is now official policy in most such areas that these modes of travel should be encouraged. How might driverless cars manage in such areas?

Most of the video demonstrations of driverless cars that I have been able to find show them performing on roads from which cyclists and pedestrians have been excluded. Where they are shown interacting with pedestrians and cyclists the pedestrians and cyclists are very occasional impediments, and the driverless cars are shown responding very deferentially. They are, according to Bridges, “inherently polite” and programmed to be “the ultimate defensive drivers”. It is difficult to see why, at the busy times of day when driverless cars would be most in demand, they would not suffer deferential paralysis in areas with high volumes of pedestrian and cycle traffic.

Bridges observes “it could be the regulatory challenges and not technology that pose the greatest risk for bringing the benefits of driverless cars to the people of the planet.” He fears that America might not rise to these challenges and asks: “Will America let politics and bureaucracy block real progress?” If not he fears that China might steal the lead in the race to bring his vision of progress to the world.

But he offers no clue as to how the challenges posed by high pedestrian and cyclist densities might be met. What regulatory changes would be needed to allow Autos free movement in such areas? His book does not acknowledge the existence of the problem. A challenge readers might find interesting: Google “China (or Netherlands) bicycles” and click on images, and then devise a set of regulatory changes that would allow Bridges’ Autos to share the streets with the traffic in the pictures displayed.

Buy this book. **** is a compromise. This is essential reading for those seeking to understand the evangelical enthusiasm of the advocates of driverless cars and the extraordinary wealth and political muscle of their promoters, and fearful of the consequences for pedestrians and cyclists who threaten to impede their progress.


PS (1 January 2016) A perceptive contribution to this theme can be found on the website of People’s Cycling Front of South Gloucestershire.


Self driving cars and the child-ball problem

“…if a ball were to roll onto a road, a human might expect that a child could follow. Artificial intelligence cannot yet provide that level of inferential thinking.”

This quotation from 2012 has already been overtaken by the extraordinary progress in the development of self-driving cars. But programming a self-driving car to anticipate a child following a ball is the easy part of the problem.  The tricky bit is programming the car’s response. read more


Risk: mathematical and otherwise

Draft of essay commissioned for a special issue (June 2015) of the Mathematics Enthusiast entitled “Risk: mathematical or otherwise”. Still time to make changes so critical advice welcomed, especially from mathematicians.


What role might mathematicians have to play in the management of risk? The idea of turning a risk, a possibility of loss or injury, into a “calculated” risk, a quantified probability of loss or injury, is one that has obvious appeal not just to statisticians and mathematicians – but to large numbers of others who would like to know the probability of failure before pursuing some intended course of action.

Conclusion: even when risks can be calculated with great precision, they can only be used to inform judgment, but not substitute for it. And it matters who is making the judgment. Read more …



A bargain

From time to time I check on Amazon to see if anyone is buying my 1985 thriller Risk and Freedom – not many.

But views about its value vary widely. The act of reading it, and transforming it into a “used” book, apparently increases its value enormously – I would like to think so..

risk and freedom


1 Comment

Risk and Freedom is a book of historic significance. Published in 1985 and out of print for many years it continues to have a profound influence on road safety policy. It provides the first coherent application of the concept of “risk compensation” to the management of risk on the road. Risk compensation is a term coined by Canadian psychologist Gerald Wilde in the 1970s to describe the behavioural adjustments of people to perceived changes in safety or danger. In Risk and Freedom Adams applies the idea to a wide variety of road safety measures – seat belts, helmets, speed limits, alcohol limits, crumple zones and other crash protection measures, improved brakes and tires, and accident blackspot treatments, to name the main ones.

The idea that risk compensation could explain the failure of such measures to achieve their promised benefits was, at the time, unanimously dismissed out of hand by highway engineers, vehicle designers, and regulators. Today it is widely accepted as mere common sense, and serves as the basis for the new, and increasingly popular, shared space schemes. The most obvious explanation for the success of these schemes is Adams’ argument that road users are not obedient automatons, but alert and responsive participants in what Adams calls in his last book, Risk, “the dance of the risk thermostats”. Also, unlike most books on this subject it is well-written and entertaining.


Global Warming: a debate re-visited.

I have posted a near final draft of what became chapter 9 of my book Risk, published in 1995. The process of writing it transformed me from a firm believer in man-made global warming into a climate change agnostic – a position to which I still adhere. In 1995 it seemed  to me that most of the explanations being offered for what was happening to the climate were extraordinarily crude and simplistic relative to the complexity of  the system that the participants in the debate  purported to understand. I choose to call myself an “agnostic” rather than a “sceptic” because this appears to me to still be the case. The sceptics cast doubt on the “fact” of anthropogenic warming – I simply don’t know.

However my sympathies have shifted in favour of the sceptics in response to the disgraceful treatment of Professor Lennart Bengtsson after he recently proclaimed his scepticism and joined the Global Warming Policy Foundation. It is difficult to imagine a scientist more honoured and qualified to comment on this issue. The vicious personal response to his expressions of scepticism to me speaks volumes for their lack of confidence in the strength of their case.

I intend soon to post a review of these almost 20 year old thoughts – after deciding which ones I still agree with.  But meanwhile …


Fun-loving singles

I recently discovered (thanks Jim) that my website had acquired a sideline in the form of a service for fun-loving singles wearing not very much, and keen to get in touch with others similarly attired. Although many of the postings might be said to have had a risk theme I have decided to focus, for the moment, on less exciting issues such as seatbelt laws and ISO 31000.

Apologies to all disappointed users of the alternative service.

Best wishes


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