Figure 3. fN-curves for British transport accidents: 1963-1992. From Evans
(1994).
The total number of casualties and fatalities accumulated through the
occurrences of a large number of events with only one or two fatalities is
much higher for road transport than for the other modes of transport.
Because of the distribution of the number of fatalities per event in road
transport in particular, the use of fN curves is not that helpful. The large
majority of fatal road accidents incur one fatality or two. Events with many
fatalities are rare and almost invariably capture the media’s and politicians’
attention with the result that actions are considered and taken which would
not have occurred, had the same number of fatalities been spread over a
large number of events. This points to a lack of rationality in terms of
decision-making on the basis of cost-benefit considerations. In the other
transport modes the frequency of events with small numbers of fatalities is
much lower. Only rail industry has a considerable number of events with
one death or more (around one hundred), compared with over five thousand
in road transport. The number of large scale disasters with tens to hundreds
of fatalities is reversed for the different modes. Merchant shipping had an
event with 189 fatalities once in a hundred years, civil aviation had an event
with 146 fatalities once in a hundred years. The corresponding figure for rail
was 49, and for road transport 32.