Methodology
There has been criticisms of various approaches to accident studies. Clarke et al. (1999)
gave a number of reasons why traditional research methods are hardly useful in road
accident research. It was asserted that accidents were relatively unpredictable and
infrequent and so, direct observation is often impossible. The use of Police files was
therefore recommended.
Grayson and Hakkert (1989) criticized the use of multidisciplinary accident
investigation (MDAI) approach on the basis that the conclusions reached are limited.
Ericcson and Simon (1980) criticized the use of self-reported interviews and
questionnaire with accident-involved road users due to forgetting and Clarke et al.
(1998) criticized it on the basis of deliberate concealment of critical information. Clarke
et al. (1998) also criticized the on-the-spot accident investigation because it tends to be
biased towards injury accidents and certain times of the day. They also suggested the
use of Police files for data collection.
However, in most developing countries, because of some limitations, Police records
are hardly accurate and sometimes insufficient to provide relevant data. As a result of
these shortcomings, a combination of the foregoing approaches were used. Field study
were combined with questionnaire and personal interviews of 400 commuter drivers,
an approach similar to that used by Milosevic (1997) in studying drivers’ fatigue. Road
Safety Commission’s and Police files were also used to verify some of the results
obtained from the field study. This resulted in the reduction of participants to 188.