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

Database Glossary Information
complicated when UK speed limits, normally recorded in miles per hour (mph),
are introduced. Conversion to kph has been employed although this does not
conform completely with the European system, table 2 illustrates the differences
in the recorded speed limits.
European Speed
limits (kph)
Converted UK
speed limits (kph)
- 32 20
- 48 30
50 - -
60 - -
- 64 40
80 - -
- 81 50
90 - -
- 97 60
100 - -
110 - -
- 113 70
120 - -
130 - -
Table 2: Speed limit comparisons
Original UK speed
limits (mph)
This method of conversion will restrict direct comparisons of speed limits
between the UK and the other partner countries, a system of grouping may be
employed to class the speed limit with road type for example.
Weather Conditions – While it is important to consider the differences in the
physical data such as those discussed above it is also useful to understand
cultural, geographic or climatic differences in order to derive the greatest value
from the data. One example of this is weather conditions, and in particular the
extremes across the 7 partner countries. For example drivers in Finland at 68°
Latitude experience extremes of cold that require completely different skills to
drivers in Italy at 40° Latitude, 4800km away. This experience of driving in
extreme weather conditions is unlikely to benefit either driver should the
situation be reversed and is therefore the cause of further restrictions in the
data.
Injury severity – The classification of injury severity and accident severity differ
significantly between the seven European partners and as a result restricts
certain analysis and direct comparison across the complete data set.
Signs – Although a common system exists for classing essential signs across
the 7 partner countries there remains a large number of signs which differ
significantly from country to country or are unique to a particular partner.
One area where restrictions exist is in the classification of the signs and
roadway for multi-laned dual carriageways/motorways. The classification for this
type of road differs between many of the partners leading to the simplification of
the ‘Motorway’ variable, this variable exists in the database as a simple Yes/No
field. This simplification restricts easy comparison of similar multi-laned roads
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