Mechanical Engineering Expert Witness Allowed in Motor Vehicle Litigation

Plaintiff sued defendants after a motor vehicle collision alleging negligent driving and negligent supervision and training of defendant’s employer.  Plaintiff hired a mechanical engineering expert witness to assist in the collision reconstruction.  Defendant filed a motion to exclude, which was denied.

Facts:  This case (Yolanda Dennis v. Ernest Collins, II, et al. – United States District Court – Western District of Louisiana – March 15th, 2017) involves a crash between a Greyhound bus driven by Earnest Collins and a GMC SUV in which Yolanda Dennis was a passenger.  After the crash, Dennis filed a lawsuit un Louisiana state court alleging that the crash was caused by Collins’ negligent driving and Greyhound’s negligent supervision, teaching, and training of Collins.  To help with her case, Dennis hired mechanical engineering expert witness John C. Laughlin.  The defendants filed a motion to exclude this expert witness testimony.

Discussion:  The defendants argue that Laughlin’s expert witness testimony should be excluded because it is not based on sufficient data or facts and that he has not applied the methods and principles of accident reconstruction to the facts of this case. The defendants do not challenge the qualifications of Laughlin.

Mr. Laughlin was tasked to determine whether the accident scenario proposed by Mr. Collins is physically possible.  He stated that he relied on numerous materials to come to his conclusions including the traffic crash report, excerpts from Collins’ deposition, and vehicle statistics.

The statistics Laughlin used include numbers such as the physical measurements as well as the performance statistics for each vehicle. Laughlin then utilized those statistics and the scenario described by Collins and put them into a computer program called PC-Crash, which is an accident simulation program.

Laughlin concluded that the scenario proposed by Mr. Collins does not conform with the geometry of the accident location and the laws of physics.

The defendants argue that Laughlin’s collision modelling is unreliable because it is based on numerous assumptions.  They find fault in the following assumptions: 1) Alfred did not jump the curb adjacent to Market Street; 2) the bus was positioned to the right side of the far lane; and 3) that there was a barrier between the I-20 ramp and market street.

The court opined that numerous experts have used the PC-Crash accident reconstruction program and experts have been allowed to testify based upon their use of the program.  In addition, the court does not agree with the argument that Laughlin’s assumptions render his methodology unreliable.

Also, the defendants have an issue with the amount of data and fats that Laughlin used when he modeled the collision.  They argue that five pieces of data were left out of his analysis to reliably come to a conclusion about the accident.  The court agreed somewhat, by stating that some courts have excluded PC-Crash testimony based on the use of insufficient facts and data.  The court in this case, however, maintains that any argument about the insufficiency of fact and data is best done on cross examination.

Conclusion:  The motion to exclude the expert witness testimony of John C. Laughlin is denied.