Glossary of Data Variables for Fatal and accident causation ... - ERSO

Manual For SafetyNet accident causation system (SNACS)
6.4 Accident investigation and different types of data
Since the Contemporary Accident Model which SNACS is based on has a wide
scope, in the sense that it includes the whole MTO-range of contributing factors,
and incorporates both sharp end and blunt end failures, the accident
investigator is faced with quite a challenge when it comes to collecting data
about accidents. This in turn, as always, calls for thorough documentation and a
number of checklists to make sure that at the end of the day, all questions are
asked and all measurements are taken.
To facilitate the on-scene procedure and the interviewing, an on-scene checklist
and an interview guide have been prepared in this manual (see Appendix D and
E) to help investigators in the on-scene work. When going out to the accident
scene, the adrenaline level is naturally quite high, and even though we may feel
calm and confident, we nonetheless tend to forget parts of the data collection
procedure unless there is a written checklist to compare with. Most likely, every
accident investigation team has their own checklists already in place, so these
have been included only for comparison and inspiration if needed.
Going out to the accident scene, there are two general types of data to be
collected. The first type regards what we can observe by ourselves on-scene,
and the second type is the data that can be collected by interviewing the people
involved in the accident (or interviewing the interviewers, e.g. talking to the
police about what the drivers and witnesses told them).
6.4.1 Observation data
Regarding the first type of data, a couple of things can be pointed out. First off,
as the accident model above implies, the context for the accident is very
important, since an axiom of the accident model is that behaviour is context
dependant. Therefore we need to be thorough and careful in our documentation
of what the circumstances were like when the accident took place, so that we
can assess the influence of the context on the development of the event. To aid
in this procedure, SNACS has, as part of the methodology, a tool for context
description and evaluation called the Common Performance Conditions
Template (described below).
Also, as we all know, careful documentation with pictures and (if possible) video
is of great value. From the experience of Chalmers Accident Investigation
Team, if the driver interview takes place after you have been to the scene,
things often turn up which the investigators were not aware of at the scene, and
which therefore warrants further analysis of the accident scene. If time and
equipment allows, it is also great to shoot a video from inside a vehicle while
driving towards the accident scene from the respective driver’s approach
trajectory, to get a feeling for what the driver experienced coming up to the
impact point. This will naturally not be a copy of the actual circumstances, but
video or pictures in an approach sequence helps the team a lot when
discussing the reasons for the accident.
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