26 Reminders For Even the Most Experienced Attorney:

The analysis of a vehicular collision involves the application of the laws of physics to the physical
evidence left as a result of a collision. This is typically completed in an effort to determine how a
collision occurred. The reconstruction analysis will provide the attorney with a foundation as to what
theories are reasonable when presenting or defending a case. Listed below are 26 reminders of items
critical to the successful utilization of a collision reconstruction engineer in the analysis of a vehicular
collision.

Steven M. Schorr, P.E., President
DJS Associates, Inc., Abington, Pa. 

Always collect the available data as early as feasible. The ability of any reasonable engineer to accurately reconstruct what occurred during a collision is a function of the available physical evidence. Data, such as tire marks, debris, roadway scrapes and the location of the points of rest of objects involved in the collision, is often “short-lived”. The earlier the data is obtained, the more data will be available to be collected.

Before you commit to any particular theory, reconstruct how the collision occurred. All credible theories will flow from the collision dynamics. Attempting to evaluate the merits of a case, without first finding out what actually occurred or what could have occurred, could create problems.

Computers are involved in all aspects of our lives. Talk to your expert about what kind of data the computers within the vehicles may yield, how to collect that data, and how might that data prove beneficial in the analysis of the collision. Additionally, ask your expert how he/she may be utilizing computers in their analysis. It is beneficial to be cognizant of the merits of such usage.

Data is the foundation of the analysis. The critical data includes the points of rest of the vehicles, the damage to the vehicles, the location and type of debris left as a result of the collision and the identification of the point of impact area. This data is the foundation of any reconstruction analysis.

Experts may be necessary to help evaluate, present, or defend your case. Be sure to utilize your experts properly. For example, just because an expert is an engineer does not mean that he/she is an expert in all engineering areas. Typical disciplines incorporated in collision reconstruction include the vehicle dynamics, the mechanical workings of the vehicle, driver responsibility and performance, traffic engineering/highway safety and human factors.

Follow the trail of the physical evidence. Many times the physical evidence will yield early identification of the issues. This identification will then allow you to evaluate the strengths and weaknesses of your case. Be sure that all of the analysis and opinions proffered are based on the physical evidence.

Gather data employing the “three-component” thought process. That is, there are three components found in every collision…the Roadway, the Vehicle and the Driver (or Human Element). Without each of these three factors, there would not have been a collision. Use these elements as a guide to data collection throughout all phases of discovery.

Human Element (the driver) is one of the three components in every collision. This category includes driver actions (and inaction), fatigue, impairment, distraction, training and qualifications. These disciplines are typically addressed by the traffic/highway safety engineer and/or the human factors expert.

Investigate all possible data sources. These sources include (but are not limited to) police investigation, newspapers, stationary traffic cameras, surveillance cameras, dash-mounted police cameras, onboard computers, fire/rescue personnel, independent photographers, witnesses, Department of Transportation photographs and video-logs, and vehicle history data.

Jack-of-all-trades. Be aware that one person cannot be deemed an expert in every area. There are specialists in all professions. Be sure that your expert has expertise in the specific subject area relevant to your case needs, and that his/her expertise is not peripheral. A collision reconstruction expert can be an engineer, but an engineer is not always an expert in collision reconstruction.

Know your client, and know your audience. As trial counsel you need to be sure that the both the ability and personality of your expert fits your case. Your expert must be able to complete the analysis in an accurate and professional manner. Your expert must be able to communicate his/her accurate opinions to you, your client and the trier-of-fact, in a persuasive and professional manner. Be sure that your expert can provide you with the state-of-the-art techniques in analysis and presentation, if the case and forum warrant such presentation.

Laws of Physics are applicable to all aspects of a collision. Any, and all, analysis must be grounded to theses fundamental principles. By applying these principles to the analysis, the credibility of your theory, and of the testimony of the involved parties or witnesses, can be evaluated. Be sure that your expert is well-versed in physics and has the ability to explain the concepts utilized in a clear and understandable manner to the layperson.

Make sure your expert has state-of-the-art technology and research available to them. This not only allows for a more complete and accurate foundation of data, but it leads, potentially, to an even more detailed analysis with more possibilities for demonstrative evidence. The utilization of state-of-the-art technology during the analysis often lowers the cost of demonstrative evidence since the exhibits have been already been created as part of the analysis process as opposed to separately.

Nice pictures can be impressive…but are they accurate? Be sure that your demonstrative evidence is accurate and unimpeachable. Conversely, be sure that your opponents’ demonstrative evidence is substantive and not just “fluff”. A collision reconstruction is an engineering process. The same precision utilized for the analysis must be employed in presenting the analysis.

Open-minded appraisal of the available data is necessary to fairly evaluate a case. If you have an understanding of the strengths and weaknesses of your case, it will be easier for you to see how a jury may view your case. Do not allow yourself, or your expert, to reach any opinions until the data is properly evaluated.

Project how you are going to present your case. The order of your witnesses may allow you to systematically and smoothly build the foundation of data that your expert will rely upon to render his/her opinions. It will also allow you to portray to the trier-of-fact the reasonable approach utilized to reach your conclusions and opinions.

Question your expert. Question your theory. Your job, and the job of the expert, is to evaluate all aspects of the collision so that you are cognizant of not only your case, but of the strengths and weaknesses of the opposing expert and counsel. Do not underestimate the need and usefulness of knowing the strengths and weaknesses of your opposition’s case.

Roadway Issues are another of the three components found in every collision. This category includes roadway design elements such as roadway geometry (curves, grades, super-elevation), traffic controls (signs, striping, signals, appurtenances), pavement properties, construction, maintenance and work zones. These areas are typically handled by the traffic/highway safety engineer.

Secure the vehicle if you have any thought that a defect, or other type of problem with the vehicle might prove to be an issue. Where, and whenever possible, try to secure any other item that may be a factor in how the collision occurred.

Testimony may be an important part of your case, but care must be taken to remember that it is not physical evidence. Testimony should be collected utilizing the “three component” thought process as a guide. To be credible, the testimony must be consistent with not only the available physical evidence, but with the laws of physics as well. People’s views and memories of an occurrence can be fallible…the physical evidence does not lie.

Understand your expert. You have a vested interest in your case. You want to understand what your expert is saying. Make sure that the analysis is clear and believable. If you cannot understand or believe your expert, just think of the problems that he/she will have convincing a juror or trier-of-fact of the value and veracity of the analysis. Vehicle issues are another of the three components in every collision.

Vehicle issues include mechanical performances of the vehicles, crashworthiness, occupant restraints (seat belts, air bags and seatbacks), fire cause and origin, on-board computers and overall vehicle maintenance. These issues are typically handled by the reconstruction engineer or automotive engineer.

Wait, if possible, before taking depositions and finishing discovery until you talk to your expert. He/she may enlighten you to additional data that can be obtained through discovery (including testimony) that would prove beneficial in the reconstruction analysis.

eXamine the procedure employed by your expert. Be sure that you understand the scope of the expert analysis, what data will be required to complete the analysis, the process the expert plans to utilize to complete the analysis and the general cost of the expert’s work. The more you are cognizant of the variables required for the expert analysis, the less chance you will be surprised by the results and/or the bill.

You are the general contractor. The expert is a sub-contractor. You must know, and understand, what your expert has accomplished and how these opinions conform with your theory and the opinions of other experts involved in your case. Your case is only as strong as its weakest link.

Zero Tolerance must be given to any variable that is known not to be ethical, accurate and/or completely “above-board”. The evaluation of the available data and applicable theories must be completed with the highest regard for accuracy and ethics. The attorney and expert should have zero tolerance for criteria that does not meet the highest moral, ethical and scientific standards.

Steven M. Schorr, PE, President of DJS Associates, Inc., is a nationally renowned expert in the areas of Accident Investigation and Reconstruction, Highway Safety and Traffic Engineering. To contact Steve about this article please call 800-332-6273 or email him at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it