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Regarding BOOK REVIEW: L S Robertson Traffic Safety Inj Prev 2005; 11: 256
[Read eLetter] More on "Traffic Safety" by Leonard Evans
Leonard Evans   (21 September 2005)
[Read eLetter] Comments on Evan's letter #2
Leon S. Robertson   (14 September 2005)
[Read eLetter] Comments on Robertson's reply
Leonard Evans   (8 September 2005)
[Read eLetter] Author's reply: Robertson's review of "Traffic Safety" by Leonard Evans
Leon S. Robertson   (1 September 2005)
[Read eLetter] Robertson's review of "Traffic Safety" by Leonard Evans
Leonard Evans   (31 August 2005)

More on "Traffic Safety" by Leonard Evans 21 September 2005
Leonard Evans,
Researcher, author, lecturer in traffic safety
Science Serving Society


Dear Editor

While difficult to disentangle what is getting Robertson so enraged, the following four possibilities seem likely candidates.

1. He denies my claim [1, p. 381-388] that US safety policy has been a dramatic failure.

2. He disagrees with my explanation [1, p 389-408] that the litigation focus of US safety policy has contributed to this dramatic failure.

3. He dislikes my book "Traffic Safety" [1]

4. He claims that its author is incapable of clear writing and technical understanding.

Let me respond in order.

1. The numbers speak for themselves.

2. Readers are encouraged to examine the considerable documentary and other evidence presented [1, p 389-408] to arrive at an informed opinion.

3. With the sole exception of Robertson's review, the book has received lavish praise by reviewers in the world's most prestigious journals. Complete details at

4. The author's writing has been accepted by 50 different publications. He has received just about every honor and award the world offers for traffic safety research. Details at


1. Evans L. "Traffic Safety". Bloomfield Hills, MI: Science Serving Society; 2004 (additional information at .)

Comments on Evan's letter #2 14 September 2005
Leon S. Robertson,
Retired injury epidemiologist
formerly Yale University


Dear Editor,

I must add to Leonard Evan's "to do" list. After getting his skin thickened, he needs courses in English comprehension and basic epidemiology.

In my letter, I said that I gave "far more" than my litigation fees for scholarships and a professorship, contrary to his claim that it all came from litigation fees. I doubt that "far more" means something in England, where Evans apparently learned to read poorly, than it does in the U.S. In fact, most of the money I contributed came from investment income enhanced by the statistical methods that Evans labels as "unintelligible hocus pocus analyses " when I apply them to motor vehicle fatality rates. My conscience is clear as to my motives for my gifts, my litigation work and my statements regarding Evan's book. Anyone who knows me and my work will laugh at Evan's allegations. Most of my scientific work preceded any thought of being involved in litigation.

Anyone who knows the behavioral science literature will wonder about someone who prefers to question his critic's motives rather than address the points I made in the review. It is not unusual for someone with bad motives to project them on others. In my review and in my articles and books, I have praised Evans' work that I consider praiseworthy, but a substantial part of the book under review is worthy only of condemnation.

Evans again raises the argument that litigation in the U.S. accounts for changes in simple counts of motor vehicle deaths in the U.S. relative to other countries. He presents no data on changes in litigation awards or litigation activity in the various countries in correlation with changes in death rates to support the assertion. In the book, he states that the inference is based on his judgement (p. 389). The word “judgement” should be preceded by “subjective”. In his most recent letter, he makes all sorts of claims about what drivers are thinking without one shred of empirical data to support his assertions, similar to the tone of many passages in his book.

Although he corrects for increases in vehicle registrations in his book, in his letters Evans relies on the 16 percent reduction in the U.S. raw number of deaths versus more than 50 percent in other countries, such as Canada, without specifying the years he is comparing. In the book, the percentages are for the years 1979-2002. Litigation did not begin in the U.S. in 1979 or therafter. The reduction in rate per vehicle given by Evans in the book is 46% for the U.S. and 64% for Canada. Thus, simply correcting for differential growth in number of vehicles narrows the difference substantially. As I said in my review, other factors must be accounted for in such comparisons: "demographic shifts, population and vehicle density in geographic areas and changing mix of vehicles", any one of which could close a gap between 46% and 64%. An epidemiology student would be flunked for making the kinds of inferences that Evans makes, without empirical analysis of the effects of such factors.

Anyone who is interested in how to reduce road-related injury should download the recent WHO report on the subject (free on the web at and save yourself the outlandish $99 that Evan's wants for a book substantially full of misinformation.

Leon S. Robertson

Comments on Robertson's reply 8 September 2005
Leonard Evans,
Researcher, author, lecturer in traffic safety
Science Serving Society

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Re: Comments on Robertson's reply

Email Leonard Evans


Dear Editor,

Once again I am indebted to Robertson for adding support to my central thesis. The fact that a chair bearing his name is endowed with his litigation profits underlines the unique influence of litigation in the US approach to traffic safety. In what other country does this happen?

In some states, such as Texas, it is illegal for juries to know that an injured plaintiff was not wearing a safety belt, as required by law. Testimony cannot therefore be presented demonstrating that obeying the belt-wearing law would have prevented or mitigated the injury (particularly true in rollovers). The incessant message to the American public is that injuries result from malfeasance by institutions with deep pockets. As ordinary citizens do not make roads or vehicles, they are led to believe that safety has little to do with them, whereas in fact the greatest reductions in risk are from small changes in behavior (such as wearing a belt). In what other country would a case about an injury prohibit mentioning safety belts?

While traffic deaths in Canada (and other countries) declined by 50%, U.S. traffic deaths declined by only 16%. My 2004 book Traffic Safety[1] associates this huge difference with an enormously powerful U.S. litigation industry pursuing money rather than safety. Critics of this thesis need to offer a more convincing alternative explanation than that U.S. legislators simply make different decisions from those in Canada. Such decisions have antecedents, including massive campaign contributions from litigators. The U.S. is a world leader in many public health areas (smoking, air safety), but its emphasis on vehicle rather than driver factors assures an ongoing catastrophe in traffic safety.


1. Evans L. Traffic Safety. Bloomfield Hills, MI: Science Serving Society; 2004 (additional information at

Author's reply: Robertson's review of "Traffic Safety" by Leonard Evans 1 September 2005
Leon S. Robertson,
Retired injury epidemiologist
formerly Yale University

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Re: Author's reply: Robertson's review of "Traffic Safety" by Leonard Evans

Email Leon S. Robertson


Dear Editor,

Leonard Evans obviously dislikes my less than totally favourable review of his book. My review noted several sensible sections in the book, but several nonsensical ones as well. My reference to self-publication of the book was only to point out that it would have benefited from peer review. His assertions in his letter regarding me and my income are patently false. He needs a skin transplant. His is too thin.

Evans notes favourable reviews of his book which I find astonishing in some respects. Inury epidemiology and prevention will not be a viable science if we stop being critical of one another's work. When I sent my review to Dinesh Mohan, who reviewed the book favourably for the British Medical Journal, he wrote back, “Leon, I agree with you! I should have read the book a little more carefully. Your review is much more detailed and sound technically.”

Evans attributes an alleged lag in adopting injury prevention in the U.S. to a "giant litigation industry" from which I "greatly profited", leading to my critique of his book. Although the U.S. led the world in requiring improved vehicle crashworthiness and laws requiring the use of child safety seats, it did lag in adoption of seat belt laws. That was not the doing of the Insurance for Highway Safety, where I was employed in the 1970s, or personal injury lawyers. At the Insurance Institute, we financed research by Australian researchers on the first law in Australia [1] and I did research which documented the success of that law.[2] I know of no involvement of personal injury lawyers in the debate regarding seat belts in state legislatures. Both motorcycle helmet use laws and seat belt use laws in the U.S. were delayed by debates regarding personal freedom, mostly by state legislators who were trying to make political hay with their constituents. Opinion polls indicated that most people opposed belt use laws at the time. I favoured such laws as any of the students who took my courses, and others who heard me lecture, can attest.

I did, for a period of time before my retirement, testify in personal injury lawsuits but I did not profit one penny from that activity. I donated all the fees I received, indeed far more (some $500,000 in total), to Johns Hopkins University, the University of Minnesota and the Trauma Foundation for injury prevention research and advocacy. If you want to call the satisfaction that I get from giving away money to support the field in which I laboured "great profit", fine. I noted in my book on my work with lawyers, free on the web at, which Evans apparently has not read, that I gave the money away and that my motivation for that work was to hold the manufacturers feet to the fire when the government stopped most of its regulatory activity in the 1980s.

Evans dismisses my analyses of safety regulation [e.g. 3] as "unintelligible hocus pocus analyses that somehow manage to find effects that support the analyst’s prior beliefs." Since Evans and I have never had a conversation, much less discussed my beliefs, he has no basis for such a charge. Indeed, I am sure the thousands of users of multiple regression analysis throughout the sciences would be surprised to see that method described as "untelligible hocus pocus". I reported what the data showed me. Indeed, I noted in my 1998 book that the regression coefficient on seat belt use in relation to fatality rates fit Evan's effectiveness estimate from his useful double-paired comparison method.[4]

It is sad that, since Evans doesn't have the facts on his side, he resorts to falsehoods in an attempt to impugn my motives.

Leon S. Robertson, Ph.D.
Retired Injury Epidemiologist
Yale University


1. Foldvary, L.A. and Lane, J.C. The effectiveness of compulsory wearing of seat-belts in casualty reduction. ACCIDENT ANALYSIS ANS PREVENTION, 6:59-81, 1974.

2. Robertson, Leon S. Automobile seat belt use inselected countries, states and provinces with and without laws requiring belt use. ACCIDENT ANALYSIS AND PREVENTION 10:5-10, 1978.

3. Robertson, Leon S. Reducing death on the road: The effects of minimum safety standards, publicized crash tests, seat belts and alcohol. AMERICAN JOURNAL OF PUBLIC HEALTH, 86:31-34, 1996.

4. Robertson, Leon S.: INJURY EPIDEMIOLOGY: RESEARCH AND CONTROL STRATEGIES, New York: Oxford University Press, 1998.

Robertson's review of "Traffic Safety" by Leonard Evans 31 August 2005
Leonard Evans,
Researcher, author, lecturer in traffic safety
Science Serving Society


Dear Editor,

While it is not customary for an author to comment on a review, a response seems appropriate to L.S. Robertson’s review [1] of my 2004 book "Traffic Safety."[2]

Another reviewer writes "Evans' work covers in remarkable detail the full range of important topics in traffic safety…but his chapter 'The Dramatic Failure of U.S. Safety Policy' is the showstopper."[3] This "showstopper" shows that while Britain, Canada and Australia reduced their traffic fatalities by 50%, US fatalities declined by only 16%. If the US had matched their performance, about 200,000 fewer Americans would have died in a two-decade period. The explanation I offer is that the US, instead of pursuing a balanced mix of interventions, obsessively focuses on vehicle factors. This focus originates from a giant litigation industry devoted to its own financial interests rather than reducing harm.

As one who supported and greatly profited from that industry, it is understandable that Robertson should seek to discredit my book. The fact that all he could come up with were extraneous trivia only adds support to my thesis.

Unable to discredit the core content, Robertson attacks the publisher. My preface [2, p.xiv] states that by not using a major publisher, "Traffic Safety" was available a year or so earlier. Given the success my 1991 book,[4] and the 27 glowing reviews it received, the present text would have been welcomed by major publishers. The six reviews to date (excusing Robertson’s!) of "Traffic Safety" have been likewise glowing. For information on reviews of both books, visit

Robertson's implication that I was unaware of the stability factor equation underlines his desperation. Its creator was, like myself, a former General Motors employee. I discuss it my 1991 book, [4, p. 76] but do not included in "Traffic Safety" because more pressing material (including factors more affecting rollover deaths) claimed each of its 445 pages. For similar reasons, I do not devote scarce space to demonstrating massive flaws in published studies as I did in the earlier book. Robertson is not cited in the present book, but often in the 1991 book.

Robertson objects to inferences from raw data, suggesting that demographic or vehicle factors can explain away the differences. Not so - - growth of vehicles, travel, etc. was similar. The vehicle mix in US and Canadian fleets is not all that different, so how can a vehicle factor explain enormous differences in safety performance?

When raw data show no indication of an effect, I have vigorously opposed unintelligible hocus pocus analyses that somehow manage to find effects that support the analyst’s prior beliefs. I have illustrated this using two frequently cited analyses of the same data (one by Robertson) that somehow ended up supporting diametrically opposite beliefs, characterizing both as "the triumph of zeal over science, or perhaps even common sense." [4, p.83].

Another reviewer writes "Evans has a clear passion for getting the right answers. For all the strong opinions he lays out, one senses that his agenda is simply to understand how to improve traffic safety."[3]

It is common in data analysis to discard a point that departs widely from the trend when there are additional reasons for considering it suspect. Robertson’s review meets such a standard.


1. Robertson LS. Review of "Traffic Safety" by Leonard Evans. Inj Prev 2005 11:256.

2. Evans L. "Traffic Safety." Bloomfield Hills, MI: Science Serving Society; 2004.

3. Eisenberg, D. Review of "Traffic Safety" by Leonard Evans. JAMA 2005 294(6), 746–747.

4. Evans L. "Traffic Safety and the Driver." New York, NY: Van Nostrand Reinhold; 1991.

Additional information at