Accident Reconstruction Science Fourth Edition

None of the recognized accident investigation texts deal adequately with low speed impacts but this book is a valiant attempt to rectify that omission. The authors are scientists and engineers who have set out to apply their practical physical experience, gained from studying the behavior of materials, to producing a solidly physics based text on vehicle dynamics and occupant kinematics. I think they have succeeded.

Low Speed Automobile Accidents was developed to provide reconstructionists, engineers, police, insurance adjusters and attorneys with the tools and understanding for correctly interpreting and reconstructing such (low-speed) collisions, and to more readily appreciate just when and how occupant injury can occur. Attorney Randall Kehl provides legal commentary on cases. A comprehensive appendix offers conversions, definitions, and newton's laws. It also explains conservation of linear momentum and torque, perception/reaction time, plus trips/flips, vaults, and roll-overs. A reconstructionist should have this book.

Previous edition of this text were titled Low Speed Automobile Accidents. Interestingly, the first edition (1996) was 270 pages, and the third edition (2003) grew to 870 pages. Watts is a consultant with several decades of experience in deciphering the physical and engineering aspects of crashes. He decided to change course with this fourth edition text by expanding coverage to all speed ranges. He notes in the preface that reconstruction is concerned with application of mathematical techniques to understand what happened, unlike investigation, which studies material evidence at the scene. Coverage encompasses general material loading responses, computer modeling methods, the energetics of collisions, and bumper behavior, among other topics.

Back in December 1996, I wrote about a book devoted to those dreaded low speed crashes. The book was the collaborative effort of three men: Alan Watts, Dale Atkinson and Corey Hennessy. Since then, the book has undergone upgrades (2nd Ed. 1999), an expansion, (3rd Ed. 2003), and now comes a revision, (4th Ed.): Accident Reconstruction Science. This time, just a single author whose impressive credentials read like a Whos Who of many people but it is about only one: Alan J. Watts, Ph.D. I do not want to merely suggest he is multitalented, but he authored or co-authored papers covering myriad topics from Spacecraft Microparticle Impact Flux Definition to "Optical Scatter due to Impact Effects to "Potential Impact Damage Effects for Short Mission Spacecraft in a Highly Elliptical Orbit. Whew! Moreover, Watts designed and developed a durable bremsstrahlung radiation converter/shield that survives high-energy impulsive loading on materials and structures for the PRONTO II test facility at Sandia National Laboratories in Albuquerque. (No, I didnt know what bremsstrahlung was either, but Ill save you from looking it up. It is electromagnetic radiation produced by the acceleration or especially the deceleration of a charged particle after passing through the electric and magnetic fields of a nucleus. Now, know any more than you did before? But I digress.) Watts designed & developed instrumentation and test fixtures while at Ktech (whose employees have comprehensive expertise in pulsed power engineering airborne flight test and satellite systems support and tracking research and development large facility operations, maintenance, and engineering) [http://www.ktech.com/]. He was chief scientist at POD (Programs on Demand) in Albuquerque, NM, a private company categorized under Research Service, established in 1994 [http://www.podassoc.com] for thermomechanical response testing for underground nuclear response tests at the Nevada Test Site. I met Dr. Watts long ago (1999) in Room H-1073 on the campus of the University of North Florida at the 17th annual session of the Institute of Police Technology and Managements (IPTM) Special Problems in Traffic Accident Reconstruction in Jacksonville. His topic: Low Speed Collisions. One might say that the man has been around the block a couple of times when it comes to the subject at hand. If you want to check him out, do NOT Google Alan Watts. You will reach 1.5 million entries, none of which is our Alan James Watts, Ph.D. You need to go to http://www.jurispro.com/AlanWattsPhD. Trust me. That site is whats called an expert witness directory. It lists his curriculum vitae and cites, via the Publications link, the title of his first book: Low Speed Automobile Accidents: Accident Reconstruction and Occupant Kinematics, Dynamics and Biomechanics. But about his new book Accident Reconstruction Science First, if you are a math nut, you will go feral and become totally engrossed around Chapter 4: Crush Responses in Two-Vehicle, Low-Speed Collisions. There are gobs more equations in Chapter 6: Energetics of Collisions. By Chapter 12, Rollovers and Side Trips, you will be ecstatic! Not to fear. If mathematical prowess is not your forte, you will still relish Watts treatment of such topics as Experiments versus Theory: Balderdash, Dishonesty and Junk Science (Chapter 11), Interesting Mechanical Models (Chapter 9), and Bumper Speed Limits (Chapter 8). However, I must admit that the text is chock-full o formulae. In addition, if algebra and trig make you squeamish, you might as well skip Chapter 16: The Heavy Vehicle versus Light Vehicle Problem. For example, there is an equation that commences on page 237, but I never quite figured out where it quits....around page 254, I think. However, there are some charts and graphs that Watts and Weintraub wedged in among those 17 or so pages. On page 327, Watts slipped in a short chapter (only two pages) on Event Data Recorders with nary a single equation, graph or chart. The author explains that he didnt dwell on EDR usage for the simple reason that the practice of reading data is precisely that: it is reading data, it is not the act of reconstructing an accident, although the data may be usefully compared with the results of a proper reconstruction. Although Watts is primarily into the biomechanical, he states: … we have renamed this fourth edition and have also removed the section on biomechanics and occupant responses. However, we retain all the biomechanical references to help those who wish to independently study the literature. In case you havent heard by now, Lawyers & Judges Publishing Co. produces legal books specializing in accident reconstruction and litigation, forensic economics, nursing home litigation, forensic science and more. If you go to their website (http://www.lawyersandjudges.com/), you might see a blurb and link to Alan J. Watts book on the sites home page. You will see where the book was Written for the recon...