Off-Road Vehicle Accidents


Off-road vehicle use and available products for the consumers to use off-road has increased dramatically over the past several decades.  With the increased use, the number of accidents resulting in serious injuries and death to the users have also increased in alarming numbers.  Many of these accidents are not caused by the users of these vehicles, but instead, are caused by the defects that are inherent in some of these off-road vehicles.  

Off-road vehicles (such as ATVs, UTVs, side-by-sides, etc.) are three-wheel, four-wheel, five-wheel, or six wheel vehicles which are "designed" for off-road use on a variety of terrains.  They are manufactured to be operated on low pressure and high flotation tires.  These vehicles are being used primarily as recreational vehicles.  However, a number of models have been designated and used specifically for agricultural and/or other utility or commercial applications.  Wright, Johnson, Carpenter, and Nelson (1991) reported that in 1990, there were approximately three million ATVs in the United States and that approximately half of the ATVs were the three-wheel units.  The CPSC (1991) reported that from 1982 to December 1990, there were more than one-half million accidents on off-road vehicles which required hospital emergency room care for the injuries and more than 1500 of these accidents resulted in deaths.  Most of the current injuries and fatalities which are associated with off-road vehicles now involve a four-wheel vehicle.

The original ATV, as we know them today, was developed in Japan by Osamu Takeuchi in the late 1960's for the Honda Motor Company.  The original objective by Honda was to develop a small vehicle that could operate on snow and, thus, compete in the snowmobile market.  Mr. Takeuchi's initial attempts were unsuccessful until the development of the high flotation, low pressure tires which were being used on other vehicles in the United States.  Mr. Takeuchi tried these high flotation, low pressure tires on vehicles of various wheel arrangements using motorcycle components.  He tried three-, four-, and five-wheel arrangements and then decided that the three-wheel design configuration with no differential and no suspension worked the best.  This design was further developed and tested in Japan and Australia and then offered for sale in 1970 as a new product: The Honda US-90 ("utility" and "snow" machine with a 90 cc engine).

In 1988, the U.S. Department of Justice worked out with the ATV manufacturers an out of court settlement which stopped the importing and sales of the three-wheel ATVs.  However, this did not stop the manufacturing, importing and sales of the four-wheel ATVs and other off-road vehicles.  Accidents are still occurring on all types of these off-road vehicles and there is a need to understand how and why these accidents occur.

As Wright, Johnson, Carpenter, and Nelson (1991) reported, most off-road vehicle accidents can usually be categorized into three basic areas:
  1. Control, maneuverability, or steering problems.    
2. Stability or overturn accidents.
3. Hand, foot, or leg injuries.

Accidents involving control or steering problems on ATVs are brought about by the fact that most ATVs have no differentials (solid rear axles) and that some ATVs have little or no suspension other than the soft balloon tires on which they ride.  Wright and Carpenter (1987) and Wright, Johnson, Carpenter, and Nelson (1991) reported that the rolling resistance or motion resistance for ATVs varied both in a turning maneuver for machines without differentials and with the deflection or deformation of the tires.  It was found, however, that there was very little variance in the rolling resistance from one hard surface to another (grass, hard soils, asphalt, and concrete).  The rolling resistance or motion resistance of the ATVs with no differentials (solid rear axles) goes up by as much as 300% as the machine is put into a tight turn.  This phenomena acts as a braking mechanism which in some cases can precipitate a roll-over due to the instability in the machine.  Steering or maneuverability and control problems with off-road vehicles are sometimes not realized by the investigating officer when writing up an accident report.  In many cases, the officer incorrectly theorizes that the operator was being inattentive or was operating the machine at speeds faster than they really were going.

The physics and mathematics of off-road vehicles' stability problems (both longitudinal and the lateral) are discussed in detail in the papers by Wright and Carpenter (1987) and Wright, Johnson, Carpenter, and Nelson (1991). Most off-road vehicles are susceptible to lateral upset or instability (vehicle tipping or rolling or flipping over on its side).  A forward pitch roll accident is where the machine and rider(s) go forward and off to the side at the same time.  A forward pitch roll is a lateral instability problem.  Tests which have been run by the present author along with others usually show that eye witnesses perceive speeds of off-road vehicles to be greater than the actual speed at which the vehicle was being operated.  On some four-wheel off-road vehicles with an operator or with an operator and passenger(s), lateral upset can occur at speeds less than 10 mph (16 km/h).  Although the tires in most cases are not defective in themselves, the use of these high coefficient of friction tires on the off-road vehicle can be a design defect.  Wright and Carpenter (1987); Wright, Johnson, Carpenter, and Nelson (1991); and Holloway, Wilson and Drach (1989) have measured coefficients of friction for various off-road vehicle tires.  As mentioned, the off-road vehicle tire is a low pressure, high contact area tire having a deep tread pattern.  Construction of most of these tires is such that they will undergo extreme deflection when lateral and/or longitudinal forces are applied.  Some of these tires will hold, let go and re-grab the surface as the sidewalls of the tire flex under lateral and/or longitudinal loads.  Thus, the tire (especially the soft sidewall tire) will jump or gallop along as lateral and/or longitudinal forces are applied.  These tires have extremely high coefficients of friction which means that they hold the surface very well and do not skid or slide very easily.  These tires will tend to scuff the ground which sometimes can be misconstrued as skid marks.

As can be seen from the preceding discussions, many off-road vehicles have considerable maneuverability, control, or steering problems in addition to stability problems during operation.  Thus, it is very important that the design of these machines consider the safety and protection of the rider(s) using these machines.  The occupant protection system on some of the off-road vehicles are non-existent or inadequate.  Consideration also must be given to the protection of the vehicle riders' feet, hands, and legs.

The present author along with others have run tests on these off-road vehicles both with and without occupants to determine if the control problems and the upset speeds which have been calculated are, in fact, valid in the real world.  These tests have borne out the information reported above.  In addition, these and other tests that have been run give a benchmark for data concerning damage to vehicles at different speeds.  Obviously, the harder surfaces being contacted (trees, other vehicles, etc.) will cause more damage to the vehicles than contacting softer surfaces such as the ground.  As the speed increases, the amount of damage to the machine also increases.  Most people do not realize that the kinetic energy carried by a machine travelling at 28 mph is approximately twice the energy of the same machine travelling at 20 mph.  Again, it is according to what surfaces are being contacted, but significant damage can occur to an off-road vehicle travelling at speeds of less than 16 mph (25 km/h).

In the investigation and analysis of off-road vehicle accidents, it is important to recognize all of accident causation factors.  Operator error such as consumption of alcohol or risk taking are sometimes causation factors.  Sometimes operator error is the only and total cause of the accident.  However, operator error is not the cause of off-road vehicle accidents as often as it is reported or claimed.  The causation factors due to design defects discussed above also have to be considered when investigating and analyzing an off-road vehicle accident.

This article discusses issues of general interest and does not give any specific legal or business advice pertaining to any specific circumstances.  Before acting upon any of its information, you should obtain appropriate advice from a lawyer or other qualified professional.

This article may not be duplicated, altered, distributed, saved, incorporated into another document or website, or otherwise modified without the permission of TASA. Contact for any questions.
Previous The New Transportation Broker Law - Map 21


Let Us Find Your Expert 

Note: This form is to be completed by legal and insurance professionals ONLY. If you are a party in a case that requires an expert witness, please have your attorney contact TASA at 800-523-2319.


Search Experts

TASA provides a variety of quality, independent experts who meet your case criteria. Search our extensive list of experts now.

Search Experts


  • I think it's always good to have access to experts when [TASA] make[s] the process so easy."

    Scott McIntosh, Lewis McIntosh & Teare, Royersford, PA

  • As a busy practitioner, managing a sizeable caseload, I can use all of the help available to me. If I can outsource a task, particularly one as important as securing a qualified expert, I will jump at the opportunity. I use TASA in nearly every case where I need to find an expert witness, be it an engineer, an architect, an economist, etc. They have thousands of qualified experts to refer in virtually any field. Best of all the process is extremely simple. When I need an expert I simply contact TASA, whose knowledgeable representatives ask you targeted questions about your case, your legal theories, and your goals, in order to find the right expert for your case. I usually receive CVs and calls from the potential expert within hours. If you find the originally selected person is not a good fit – for whatever reason – TASA will work with you to find the right person. I would happily recommend this service to any attorney."

    Patrick K. Gibson, Gibson & Perkins PC, Media, PA

  • Ms. Darlie I. McDonald RN was awesome on the witness stand, and we prevailed in our case to the tune of  [a] (highly unusual [amount] for a medical malpractice [case] in our area).  I'd highly recommend her."

    Shane Reed, Shane A. Reed Law Office, Jacksonville, OR

  • I appreciate your inquiries and offers of assistance as well as the consistently high-quality, well-organized, and erudite TASA webinars, which invariably have excellent presenters."

    Maurice S. Kane, Cummings McClorey Davis Acho and Associates PC, Riverside, CA

  • Steven Kursh was an outstanding technical expert on our ecommerce IP lawsuit. He completed a massive amount of work on extremely complicated material, in a very short period of time. His work product was first rate and I think he would have done a terrific job if the case proceeded to trial. He is very articulate and helped us. I only wish we had gotten him involved sooner in the litigation."

    Daniel J. Brown, Reiss Sheppe LLP, New York, NY

  • I thank you all for the response to my request for an expert witness...Both Mr. Scott and Mr. Bianchi appear to be well-qualified for this case, but we have hired another expert. As always, I was impressed by TASA's ability to produce exceptionally well-qualified candidates with great speed."

    John Thomas Dzialo, The Law Offices of John Thomas Dzialo, Santa Ana, CA

  • Thank you for your quick response and the names of the two proposed experts. The situation that gave rise to our search for these experts has resolved and we will not need to retain them. However, we will continue to keep TASA in mind as these needs arise from time to time as your breadth of coverage for experts of all types is unparalleled, in my experience."

    Bart W. Brizzee, County of San Bernadino, San Bernadino, CA

  • I have used TASA for the last five years for locating an expert for many personal injury cases. On each and every occasion, TASA was able to find me more than one qualified expert. With such a variety of experts, I was able to select one who met my client's needs in prosecuting these claims. I found the experts TASA referred not only qualified, but available on a moment's notice. Your fees are reasonable and fair, and I will continue to use TASA for the remainder of my career."

    Robert Oushalem, Esq., The Law Office of Robert Oushalem, San Jose, CA

  • I recently used TASA for the first time to locate an expert to testify in a case requiring rather unusual expertise and where there were no applicable regulations or standards for guidance. TASA referred an expert in California who was everything a lawyer looks for in a forensic expert. He was promptly available for consultation, efficiently prepared for deposition and trial and very persuasive and credible with the jury. TASA's administrative services and assistance in locating this expert were excellent, and we would certainly use both the expert and TASA in the future."

    Theodore Phillips, Miller Hauser Law Group, LLP, Placerville, CA

  • TASA has always given me first-class service, but in a recent matter, TASA found the 'needle-in-the-haystack' expert witness we feared didn't exist. We needed an expert for a very narrow and limited issue in a very narrow and limited industry. Because TASA has an extensive expert witness database, it was able to give us a referral almost on the spot. It's why I always turn to TASA first."

    Kathleen A. Herdell, Law Offices of Kathleen A. Herdell, St. Helena, CA

  • There are numerous companies that provide litigation experts. However, I always choose the TASA Group because of their quick response in finding a qualified expert for my particular case. I have extreme confidence in the TASA Group and will continue to use their services in the future."

    Katie A. Killion, Esq., Chiurazzi & Mengine, LLC, Pittsburgh, PA

  • I spent hours trying to locate an expert in a very technical case involving a defect in a medical device. I could have saved a lot of time by calling TASA first. Within hours, I was supplied with the name of an engineer who had more than 30 years of job training, education and expertise in the precise area involving the device. Bravo TASA!"

    Timothy W. Peach, Partner, Peach & Weathers, San Bernardino, CA

  • We were involved in a case pending for more than five years with seven parties from three states. Three mediations failed before we looked to TASA for an expert. TASA referred an expert who clearly understood the complexity of the project and could effectively support his opinion. If it weren't for his expert advice and deposition testimony, the case would not have settled. Interestingly, the case settled within 90 days from the date this expert began."

    Renee Colbert, Esq., Corporate Counsel, W.G. Tomko, Inc., Finleyville, PA

  • Using TASA to find experts for defending our client in a negligent homicide case ended up being one of the most important decisions we made in trial preparation. The experts they suggested were exactly what we needed for the case. I truly did not expect to find experts that would be such a perfect fit for the nature of case. TASA provided us with highly qualified experts in somewhat narrow fields of expertise. A large percentage of our victory is due to the experts recommended by TASA."

    Marta Farmer, Esq., Carl S. White Law Office, Haver, MT

  • I have used TASA's services since the 1980's and have never been disappointed. TASA is indispensable for locating that hard-to-find expert. TASA representatives have always been courteous and pleasant, with the attitude that they cannot do enough to help. I expect to continue using TASA throughout my career."

    Brad W. Greenberg, Esq., Smyth Law Offices, P.C., Brockton, MA

  • I needed to retain a multitude of scientists from a variety of disciplines for a complex litigation. Initially, I went through a series of interviews with an extremely knowledgeable and professional team of TASA advisors. They were able to find highly qualified experts in the specific fields, all of whom turned out to be superior in qualification and area of expertise to my adversary’s experts. I am a TASA believer!"

    Nooshin Namazi, Partner, Nicoletti Hornig & Sweeney, New York, NY

  • TASA always comes through in the difficult IP cases. Their representatives work with you to refine the search criteria and quickly send you a list of very qualified experts."

    Timothy L. Boller, Principal, Seed Intellectual Property Law Group, PLLC, Seattle, WA

  • Special thanks to our TASA referral advisor for her quick response to our initial request—we were extremely happy with how fast TASA was able to assist us! Your group does excellent work, and it is always my first stop when looking for an expert."

    Susanne K. Sullivan, Senior Attorney, Southwest Airlines Corporation, Dallas, TX

  • When we needed an expert in a patent infringement lawsuit, we turned to TASA. We were looking for a witness qualified in two unrelated technical areas, and TASA worked with us to identify and refine our requirements. TASA performed well, promptly providing us with several excellent candidates to consider, one of whom we retained."

    Joseph T. Miotke, Partner, IP Practice Group, Michael Best & Friedrich LLP, Milwaukee, WI

  • Our team had a very positive experience with TASA. The Expert was professional, efficient, and certainly an expert in his field. His work and testimony contributed to a winning decision for our client! We will recommend the Expert and TASA whenever appropriate."

    Stephanie Sprague, Esq., CT

  • (The Expert) WAS A PERFECT FIT for my case: qualified, competent, easy to work with, attentive to detail, knowledgeable, smart, communicative, enthusiastic, resourceful—have I left anything out? I highly recommend TASA and would be happy to share my experience with anyone else. Thank you!"

    Michael Porrazzo, Esq., The Porrazzo Law Firm, Mission Viejo, CA

  • The expert was very thorough. TASA was quick to respond with an answer to my request. I have used TASA in the past under various other law firms and have been pleased. TASA continues to live up to expectations and then some."

    Anne Desormier-Cartwright, Esq., Jupiter, FL

  • Your organization found us an appropriate expert witness in less than one day. This was excellent service. The expert you found was excellent and a pleasure to work with."

    William A. Ehrlich, Esq., Allentown, PA

  • (The Expert)…accomplished exactly what we wanted. TASA was very prompt and efficient in locating him. All fees were reasonable."

    J. Michael Lehman, Esq., Bruce, Bruce, & Lehman, Wichita, KS

  • We needed an Internet expert right away to meet a deadline. One phone call to TASA, and in less than a day, TASA called back with a list of 8-10 experts who were exactly what I needed. The TASA expert I chose knew the business and mechanics of the Internet so well—he was a PhD and professor who had written a book on the subject—that he put the fear of truth in the defendant that caused him to settle. When I get the kind of service that I did from TASA, I stick with it and use it again and again."

    Philip Green, Attorney at Law, Green and Green, San Rafael and San Francisco, CA

  • Excellent—in a word. I just do not have the time to hunt for experts. (The Expert) was fantastic. Thank you for providing such a quality service."

    Francesca Carinci, Esq., Steubenville, OH

  • TASA stands for Tops At Serving Attorneys. It’s always rewarding working with TASA."

    Marshall A. Bernstein, Esq., Philadelphia, PA.

  • That was, however, one of the best and most interesting webinars I've seen in the last few years.  Thank you for hosting it and introducing me to such a knowledgeable and caring person." - Referencing the Medicolegal Consequences of Post-Traumatic Stress Disorder in Civilian and Military Populations webinar. 

    Lori Bauer Apodaca, The Law Office of Lori Bauer Apodaca, Los Lunas, NM 

  • I needed a dental malpractice expert to assist me in a complex negligence claim. The very able staff at TASA had no difficulty identifying a knowledgeable professional who rendered a reasonable opinion in support of the case, which aided our client in receiving a fair amount of compensation. I am grateful to TASA for its invaluable assistance!"

    John Hermina, Hermina Law Group, New York, Pennsylvania, Maryland & Washington, DC

  • For many years I have relied upon TASAmed to provide excellent medical malpractice experts. As a sole practitioner, I find it reassuring to know that a seasoned expert is just a call away. Usually, TASAmed has found just the right expert in a day or two. The support and guidance I receive from TASAmed is a vital part of my law practice, and I have come to expect both great service and high rewards from my TASA cases."

    Thomas J. Massey, The Thomas J. Massey Law Firm, Fallbrook, CA

  • The caliber of physicians that TASAmed has referred to us is superb. Prior referral groups used the same experts over and over again. With TASAmed I have access to experts all over the United States. I’m not limited to the same experts. The TASAmed staff is easy to work with and very professional, with an established track record. When I call for a medical expert, I’m called back the same day, and I often have an idea of what expert will be contacted before my first call is completed."

    Kari Alexander, Certified Legal Nurse Consultant, Texas

  • We hadn’t been able to find the medical expert we needed, and, frankly, I didn’t think we’d find one in that field. TASAmed was able to find us an expert with the exact expertise and medical experience we needed. Your referral advisor was very helpful and found our expert in one day."

    Kurt Osenbaugh, Partner, Alston & Bird, Los Angeles, CA

  • TASAmed’s service was prompt and efficient in connecting us with the right person. The expert was so cooperative and helpful. With how challenging it is to find a narrow area of medical expertise, it’s extra helpful to have your TASAmed pool to plug into instantaneously."

    Greg Roosevelt, Esq., Law Office of Greg Roosevelt, Edwardsville, IL

  • TASAmed has connected me to credible experts in four medical cases just this year. TASAmed and the referred experts respond quickly, the fees are reasonable, and the referrals are well tuned to the fields I request. Since the experts are already associated with TASAmed, they are comfortable having substantial conversations about the case, both before and after record review."

    Martin A. Cannon, Esq., Cannon Law Offices, Crescent, IA

  • I have used TASAmed a number of times and have always been happy with your give-and-take timeliness. Once I requested a medical expert in a particular field, but, after speaking with your referral advisor, we concluded that an expert in another field would be more effective. That same day, I spoke to two experts the advisor gave me, and I retained one."

    Mark A. Lope, Esq., Lope and Honlihan, Butler, PA

  • Very close to the time of trial, the TASAmed advisor quickly referred me to several experienced ER trauma physicians to review medical records and prepare me for cross-examination. After selecting my expert, I over-nighted records for review, and the doctor found valuable information for my client's defense. Thank you, TASAmed, for this timely, specific, valuable referral."

    Charles Morgan, Esq., Law Office of Charles L. Morgan, Jr., Charlotte, NC