Center for Injury Research and Prevention

Low Acceleration Time Extended Events

Low Acceleration Time Extended Events sled
CIRP and Drexel University researchers prepare a participant for a test of the LATE sled.

While many crash test protocols involve a vehicle hitting an object head-on or directly from the side, that is not wholly representative of a typical real-world crash where the driver anticipates the danger and swerves to either avoid contact or minimize damage. The Low Acceleration Time Extended Events (LATE) project aims to quantify the movement of passengers of different ages during these types of pre-crash avoidance maneuvers.

CIRP researchers from CHOP and Drexel University have collaborated to create a sled that mimics vehicle swerving. This multi-year line of research seeks to define how occupants move as a result of this swerving and how vehicle restraints interact with the occupant during these maneuvers before a crash ever occurs.

Initial testing is examining "unaware rear-seated passengers" in several different conditions:

  • Baseline - no bracing, restrained in a typical rear seat belt in a typical rear seat
  • Bracing and restrained in a typical rear seat belt in a typical rear seat
  • No bracing and restrained in a more advanced front seat belt (i.e., with load limiters and pretensioners) in a typical seat
  • No bracing and restrained in a more sculpted seat

Video, electromyography (EMG, a measure of muscle activity), and motion capture data is captured on each test subject in all conditions. Initial data suggests that participants who brace for swerving have little visible movement, while the EMG data shows their muscles and tendons actively responding to the swerving.

Principal Investigator: Kristy Arbogast, PhD
Funding: TK Holdings Inc. (Takata Corp.)

Click here to read an Injury Science Research Experiences for Undergraduates student's perspective of working on this project. 

Click below to view a demonstration of the test sled as seen on Discovery Channel's Daily Planet.