Figure 4: Time series events to an accident produced using Google Sketchup.
3. ANALYTICAL TOOLS FOR
RECONSTRUCTION
All available evidence collected must be analysed,
correlated and interpolated to determine what
may have caused the accident to happen. The
analyses include data processing, evaluating
possible hypotheses, creating models, recreating
accidents, and may also involve simulation
software.
Today, the reconstruction methodology has
been revolutionized by the use of powerful,
inexpensive computers and special software.
Various types of software are now available and
some commonly used in accident reconstruction
work including Google Earth, Google Sketchup,
CAD programmes, momentum and energy analysis
programmes and photogrammetry software.
The combination of the output from these
software can help the investigator carry out
post-accident measurements, especially if
the investigator was not able to perform all
the measurements due to time constraint or
any other reasons that might have arisen. The
results obtained can also be used as input in the
reconstruction simulation software, PC-Crash -
Collision & Trajectory Accident Reconstruction
Software, to simulate different events to
demonstrate the consequences leading to the
crash. In the simulation package, 3D features are
applied in the reconstruction process.
Whenever animations are used for legal
purposes, they must be meticulously detailed and
carefully scrutinised based on physical evidence
and calculations which embody the laws of
physics. A physically realistic animation needs to
be created by someone with a good knowledge
of physics, dynamics and engineering. Animation
typically depicts all or part of an accident
sequence in a video format so that non-technical
or interested parties, can easily understand the
expert’s opinions regarding an event.
The investigator will then compile the report
findings, diagrams, including animations, to form
their expert opinion, testimony and conclusions
relating to the accident. A good report is valuable
information for the authorities or stakeholders to
make sound decisions on any of system design
changes that may be required, thus addressing
improvement needed in highway design and
facilities, and policy review for the betterment of
road conditions and safety of road users.
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