Accessing and Interpreting Heavy Vehicle Event Data Recorders

Recent advances in commercial vehicle equipment have increased the potential for incident-related data to be recorded surrounding a collision event. What some have called a "black box" is more properly referred to as a Heavy Vehicle Event Data Recorder (HVEDR) as defined by the SAE J2728 HVEDR Recommended Practice. The term HVEDR is used to describe any type of electronic function that has the capability of storing data surrounding a defined event within an electronic control module found on a heavy truck or bus and that communicates on the SAE J1939 or J1587/J1708 data communications protocol. This course highlights the various vehicle systems and triggering events that may provide data useful in a collision investigation. Guided by recognized industry experts, techniques for preservation and interpretation of HVEDR data will be explored. This highly interactive workshop includes in-class instruction, demonstrations and practical hands-on experiences for acquiring and analyzing data from commercial vehicles.

This course will include discussions on the four standards. Anyone who wishes to do so can purchase these ahead of time by contacting SAE Customer Service. Please note: purchasing the SAE Standards is not required.

This course has been approved by the Accreditation Commission for Traffic Accident Reconstruction (ACTAR) for 24 Continuing Education Units (CEUs). Upon completion of this seminar, accredited reconstructionists should mail a copy of their course certificate and the $5 student CEU fee to ACTAR, PO Box 1493, North Platte, NE 69103.

Please note, attendees are required to bring their laptops to this seminar to utilize the electronic handout materials. Not required but we highly encourage students to bring their HVEDR download computers and hardware to participate in hands-on data extraction and analysis using their own tools. 
Note: Last day of class ends at approximately 12:30 pm.

What Will You Learn

Upon completion of this workshop, you will be able to:
  • Identify the potential sources of HVEDR data available on commercial vehicles
  • Utilize various methodologies for accessing and imaging data from HVEDRs while preserving the data in its original electronic format within the control module
  • Compile documentation of the vehicle and the imaged HVEDR data to properly establish foundational facts that tie the data to the vehicle and to ensure the reliability of incident specific data
  • Properly interpret data from HVEDRs and understand the limitations of this data
  • Analyze HVEDR data in the context of collision reconstruction

Is This Course For You

This course is a must for anyone involved in the investigation and analysis of commercial vehicle crashes who needs to understand the types of event data that are available on commercial vehicles, how it is generated, how it is accessed from the vehicle, and how to apply it in a collision reconstruction. In addition, this course can be valuable to the motor carrier safety manager, independent adjusters, claims managers or attorneys handling commercial vehicle collisions.

Materials Provided

This data is not available at this time

Course Requirements

This data is not available at this time


  • Primer on Multiplexed Vehicle Electronics Systems and Vehicle Data Networks
    • Network architecture -- SAE J1587/J1708; SAE J1939
    • Industry standards for EDR devices -- SAE J2728; TMC RP1210; Other industry standards; Potential government regulations
  • Accessing and Imaging Data
    • Through in-cab diagnostic port
    • Direct to module (benchtop)
    • Truck-in-box simulators
  • HVEDR Devices and Data Currently Available on Heavy Vehicles
    • Engine control systems --Detroit Diesel; Mercedes-Benz; Cummins
    • Small Group Hands-On Imaging HVEDR Data
  • HVEDR Devices and Data Currently Available on Heavy Vehicles (continued)
    • Electronic Control Units - Caterpillar; Mack; Volvo; International; PACCAR
    • Active Safety Systems - VORAD; ABS & Stability Control Systems; Collision Warning & Active Braking Systems; Lane Departure Systems
    • Small Group Hands-On Imaging HVEDR Data
  • Inspecting the Vehicle
    • Chassis & powertrain identification and health
    • Vehicle configuration
    • Collision damage
  • Validation Studies and the Accuracy/Reliability of HVEDR Data
  • Interpreting and Applying HVEDR Data
    • Determining whether data imaged from a HVEDR is related to an incident of interest
    • Determining where impact occurred in dataset
    • Comparing vehicle speed to engine speed
    • Determining gear selection
    • Determining travel distance
    • Determining acceleration/deceleration
    • Determining driver inputs
    • Rollover signatures
    • Rear impacts
  • Group Projects
    • Students will split into small groups and will work on a group project that will include a vehicle inspection, skid mark measurements, HVEDR imaging, and analysis of the HVEDR data and comparison to the documented physical evidence. Note: Students will want to wear appropriate clothing to inspect a heavy truck. Also, students may want to document their project with cameras, camcorders, tape measures, etc.
DAY FOUR (Formal class ends at 12:30 pm; students may have additional hands-on practice beyond 12:30 pm as long as the trucks remain available)
  • The Future of HVEDR
  • Hands-on Workshop