I just made a proposal to the Society of Automotive Engineers (SAE) for a new course titled “Applying Automotive EDR Data to Motorcycle Accident Reconstruction.” Here are some of the specifics, which I would love your thoughts on. What would improve this concept? What would make this course more useful? I’ll be offering this course for the first time on November 6, 2019 in Denver, along with Alan Moore’s class “Accident Reconstruction, the Automomous Vehicle and ADAS” (November 5) and Neal Carter’s new class on using drones for mapping accident sites (November 7). Hold these dates if you are interested…more info to come.
Electronic event data has become ubiquitous on modern passenger vehicles. This data will often contribute useful information to the reconstruction of a motorcycle collision with a passenger vehicle, information that may not be accessible in any other way. However, reconstructionists will need to understand how the data is collected and its limitations, particularly when analyzing motorcycle crashes where a significant weight discrepancy between the motorcycle and the passenger vehicle can make the analysis very sensitive to potential errors in the EDR data. Issues of interpretation and accuracy arise that will often require the reconstructionist to employ classic reconstruction methods alongside the data from the event data recorder (EDR). Also, many motorcycle crashes will raise questions that go beyond what the EDR data can directly provide, and many accident reconstructions will need to draw on a broad swath of evidence – physical, video, audio, and testimonial, in addition to the electronic data.
Some motorcycles now have EDRs and the possibility of there being electronic data from the motorcycle involved in a collision now exists. This scenario remains rare, however, and the more common scenario is that the struck passenger vehicle will be equipped with an EDR. This EDR data will give useful information but will not directly report the collision speed of the motorcycle. The electronic data can, however, be combined with classic reconstruction techniques to infer the collision speed of the motorcycle, to reconstruct the speed and path of the passenger vehicle in the moments leading up to the collision, and to understand errors that the driver or rider made in the moments leading up to the collision.
This class will equip students with the skills to incorporate EDR data into a reconstruction of a motorcycle collision and to reconcile it with other types of evidence. The class will cover the unique features of motorcycle crashes that influence how both the pre-crash and crash data should be interpreted and incorporated. It will cover common error sources in EDR data and how those can be corrected for in a reconstruction. The class will also cover the data that may be available from a motorcycle EDR. Finally, this class will present several case studies that will provide a guide for incorporating EDR data into a reconstruction. Students will have the opportunity to practice the analysis methods through several in-class exercises.
By attending this seminar, you will be able to:
1. Recognize common sources of error in pre-crash and crash EDR data that are applicable to motorcycle accident reconstruction.
2. Apply vehicle inspection techniques for ruling out some of these error sources.
3. Apply principles of physics to account for and correct for other error sources.
4. Apply reasonable error and uncertainty rates when incorporating EDR data into the reconstruction of a motorcycle crash.
5. Incorporate EDR data with other analysis techniques to obtain a reasonable and accurate reconstruction of a motorcycle collision with an EDR-equipped passenger vehicle.
Course Content (1 day)
Overview of Methods for Analyzing Motorcycle Collisions (1 hour)
o Wheelbase Reduction and Car Crush Methods
o Translation and Rotation of the Struck Vehicle
§ Equations for Vehicle Spin
o Conservation of Momentum
Overview of Passenger Vehicle and Motorcycle EDR Data (1 hour)
Common Error Sources in EDR Data that Affect Motorcycle Accident Reconstruction (1 hour)
Passenger Vehicle and Motorcycle Inspection Techniques for Ruling Out Some Error Sources (0.5 hours)
Analysis Methods for Eliminating or Accounting for Other Error Sources (1.5 hours)
o Applicable Error Rates for Pre-Crash and Crash Data
o Discrepancies between the ACM location and the Center of Gravity
o Accounting for Tire Forces during the Collision
Case Studies and In-Class Exercises (1.5 hours)