Negligent Design Engineering Allegedly Causes Off-Road Vehicle Accident


Engineering Expert

Court: United States District Court for the District of Arizona
Jurisdiction: Federal
Case Name: Thompson v. Polaris Indus.
Citation: 2019 U.S. Dist. LEXIS 81103

In this personal injury case involving an off-road vehicle accident, the plaintiffs presented an expert with decades of experience in off-road vehicle training but no formal education to opine on the vehicle’s design. It was determined by the court that an expert called to opine on engineering issues without any formal education (qualified exclusively by experience) can only testify if his knowledge is based on sufficient data and specific methodology properly applied to the facts of the case.

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In February of 2014, the plaintiff, Mr. and Mrs. Thompson, rented a Polaris RZR off-road recreational vehicle from the defendant, Jet Rent, in Yuma, Arizona. The vehicle was designed, manufactured, and sold by Polaris Industries, Inc. While the plaintiffs were traveling in the vehicle in question, the vehicle rolled over and both the plaintiffs suffered serious injuries. The plaintiffs filed a complaint against the defendants Polaris Industries, Inc. and Jet Rent alleging liability, negligence, and punitive damages. In October of 2018, the court dismissed Jet Rent, leaving only the first two claims against Polaris.

The Expert

The plaintiffs retained an expert in off-road vehicles to discuss the design of the vehicle in question. The plaintiffs’ expert had more than 30 years of experience working as an off-road vehicle operation instructor. He had also served as an expert consultant for governmental agencies and public companies in a similar capacity. During the course of his career, the plaintiffs’ expert had developed and taught courses on the safe operation of off-road vehicles for various agencies.

The expert provided an analysis of the “vehicle design parameters related to occupant safety, including the appropriate safety equipment required for each vehicle based upon its geometric design, operational characteristics, and environment of use.”

Based on his analysis, the expert opined that “Polaris failed to eliminate the tendency for the RZR to tip and roll over even during routine maneuvers going down a slope or on flat ground, simply by turning the steering wheel too far too fast.” He further asserted that the vehicle in question was susceptible to oversteering.

The defendants challenged the qualifications of the plaintiffs’ expert, claiming he lacked the requisite qualifications to opine on off-road vehicle design.

Court Discussion

The defendants claimed that the said expert had no formal education related to engineering and his expertise was based only on his real-world experience. The defendants pointed out that the expert lacked formal education or training in engineering, accident reconstruction, or human factors. Furthermore, the expert’s highest level of education was a high school degree.

The defendants challenged the said expert qualification to make opinion relating to the designing of the various system of the said vehicle in question claiming he had no experience designing ROPS or vehicle restraint systems.


The court granted in part the motion to exclude the plaintiff expert’s testimony and denied it in part. The court held that the plaintiffs’ expert was not permitted to testify regarding the specifics of designing ROPS or restraint harness systems since he did not have enough knowledge on the subject such that his testimony could be relied upon.

With regard to the expert’s opinion regarding the availability of alternate design of steering, the court held that due to his lack of knowledge regarding the subject matter and lack of basis for his opinion, he was not permitted to opine on this issue. The court also found that the reasoning and methodology used by the expert was inadequate because he did not have any formal education.

However, the court allowed the expert to opine on the handling characteristics of the vehicle in question, as he had plenty of experience operating off-road vehicles, consulting government and private agencies, and providing training for operating off-road vehicles.  It was determined that the expert was only allowed to testify to the steering characteristics of the vehicle in question.