ACTAR Evidence Collection 5

Question 1

Which characteristic of a crush damage profile is MOST useful for determining the vehicle's closing speed in a frontal barrier equivalent (FBE) analysis?

Accepted Answer

The depth and distribution of crush across the vehicle's front

Answer

Crush depth and its distribution across the vehicle width are the primary inputs to stiffness-based (Campbell) energy methods used to calculate delta-V and closing speed.

Question 2

A reconstructionist finds a gap in the skid mark evidence where tires momentarily stopped skidding before resuming. This gap most likely indicates:

Accepted Answer

ABS activation cycling during the braking event

Answer

ABS systems rapidly modulate brake pressure, causing the tire to alternately lock and release, producing characteristic gap patterns in the mark sequence.

Question 3

When surveying a crash scene that spans multiple lanes of a highway, what is the preferred sequence of evidence documentation before any scene is cleared?

Accepted Answer

Overall scene photographs, then close-up photos, then measurements and sketches

Answer

Overall photographs establish scene context, close-ups capture specific evidence detail, and measurements/sketches follow to minimize scene disruption and preserve spatial relationships.

Question 4

The Daubert standard, as it applies to crash reconstruction evidence, requires that the expert's methodology be:

Accepted Answer

Based on peer-reviewed, testable science with known error rates

Answer

Under Daubert, courts evaluate whether scientific testimony is based on sufficient facts, uses reliable methods that have been tested and peer-reviewed, and whether the method has been applied reliably to the case facts.

Question 5

Which EDR data parameter is MOST directly useful for determining whether a vehicle's brakes were applied in the 5 seconds before a crash?

Accepted Answer

Brake switch status recorded in the pre-crash data frame

Answer

EDR pre-crash data records brake switch status on a time-stepped basis, directly indicating whether the driver actuated the brake pedal and when.

(ACTAR) Accreditation Commission for Traffic Accident Reconstructionist Practice Test

(ACTAR) Accreditation Commission for Traffic Accident Reconstructionist Practice Test

ACTAR Evidence Collection 5