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

Manual For SafetyNet accident causation system (SNACS)
Common Performance Conditions - Dimensions, parameters and evaluation levels
CPC Parameters Explanations Comments Evaluation level /
influence on
driving
performance
Source
of info
(inspection of
car, interview
with driver, etc)
Quality of
info
very reliable (+)
reliable (0)
less reliable (0)
not reliable (-)
Design of traffic
environment
Type of traffic
environment
Important factors
Complexity
Information
What kind of traffic environment was
it
Within or outside urban area
Main road or highway
Any important factors which
significantly makes it easier to drive or
are there any risk factors (road
construction work, hidden exits,
unusually tight curve radius, holes in
the road, ect)
Within urban area Country road (0)
City traffic (-)
No information Several supportive factors (+)
No obvious risk factors (0)
Some risk factors (0)
Many risk factors (-)
How complex is the traffic
environment
Crossing roadways (crossing,
circulations, exits, etc)= complex
Several lanes in any/both directions =
moderately complex
One lane = not complex
Intersection Not complex (+)
Moderately complex (0)
Very complex (-)
Is the signing clear/easy to
Functioning traffic ligtht,
understand
adequately placed
Are the road markings clear
Is information provided early enough
for the driver to have time to react
Is crucial information missing which is
needed to pass the spot safely
Figure 17: Example of partial CPC evaluation
Supportive (+)
Adequate (0)
Tolerable (0)
Inappropriate (-)
inspection on
scene
inspection on
scene
inspection on
scene
very reliable (+)
very reliable (+)
very reliable (+)
6.7.3 Choice of Phenotype
After you have evaluated the CPC it is time to start the SNACS analysis. NOTE:
The task is to do one analysis per vehicle involved. The circumstances can
be evaluated as a whole (except for the driver specific dimensions of course),
but the contributing factors need to be evaluated for each vehicle in turn.
To do this, take out appendix B, and locate the first table of the appendix, which
is named PHENOTYPES. This table contains all the available phenotypes and
the possible sets of genotypes that can link to each phenotype. An extract from
the table for the phenotype TIMING (A1) looks like this:
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