Beyond the Last Precrash Speed Value

DATE: Friday, 05 December 2025
TIME: 12 noon - 2pm EST (GMT-5, or 9am-11am Pacific Time)
COST: Free for NAPARS members;  $6 for non-members
ACTAR: This event will be submitted to ACTAR for CEU consideration.

All attendees will be able to request an attendance certificate during the show.

The show will be recorded and put in the Reference Library along with various supporting material.

Crash investigators often open an EDR report, look at the last speed value recorded, and say, "That's the speed at impact." And while it _might_ be true, one can be terribly mistaken. Also, failing to examine the rest of the report leaves a ton of information on the table - yaw rate, steering angle, brake fluid pressure, wheel speeds, and actual precrash acceleration, for instance. This session will explore extracting that data from a report and using it to understand the whole event. We will discuss the mechanisms of traction and steering that manifest in the sensor data.

     -A little history
     -Where is speed data coming from?
     -Making tabular data useful
     -Vehicle Dynamics and Friction
     -Newer = more sensors & more data = opportunity to answer lots of questions:
     -What is the driver doing with the controls?
     -What is the car commanding?
     -What is the chassis experiencing?
    -Confirming data with multiple sensors

SPEAKER: Wade Bartlett has over 30 years of experience in all aspects of crash reconstruction, focusing heavily on friction, motorcycles, and EDRs. He is a licensed Professional Engineer in NH, holds ACTAR #789, and has been a part-time police officer in NH since 2003. He occasionally teaches for IPTM. He is the administrator of NAPARS.

Wade chasing EDR data around 2004.