Technieken voor de observatie en analyse van verkeersconflicten

English summary
Title Techniques for the observation and analysis of traffic conflicts
Subtitle Literature study
Abstract
The roots of the Traffic Conflict Technique (TCT) are situated in the fabrics of General
Motors in Detroit. At the end of the sixties, the car manufacturer developed observation
techniques to determine into what extend cars of General Motors were involved in unsafe
traffic situations (Perkins & Harris, 1968; Archer, 2001). A traffic conflict was defined as
every possible conflict situation leading to braking or manoeuvres.
Conflict observation techniques start from the assumption that the behaviour of drivers is
a valuable source of information in the case of potential conflicts (Hydén, 1987; Horst,
1990). Only a small amount of all passages lead to fatalities. The share of potential
conflicts is already bigger. Through the analyses of potential conflicts insight can be
gained in factors en patterns underlying unsafety. This information can be used as
additional information to accident data and can be used by road authorities when taking
a well funded decision about the renovation of intersections and stretches.
The use of conflict observation techniques is divers:
as instrument for diagnosis of unsafe locations,
formulation of theory: for in depth investigation of aspects causing unsafe situations,
carrying out evaluations of the effects of measures using before and after studies,
determining criterions for setting priorities in a programme for road safety research.
An important advantage of the use of traffic conflict techniques is the fact that research
of the road safety of a certain location can be carried out within a short period of time.
There is no need to wait for statistical relevant accident data. Moreover, research can be
adapted to the specific characteristics of the situation which allows gaining insight in the
relation between behaviour of the road users in relation to the build environment. When
using cameras, research results can be linked to more general data about weather,
amount of vehicles and speed. Furthermore, footages can be used when discussing the
results of the research with stakeholders and the responsible authorities.
Traffic conflict techniques also have limitations. Carrying out observations is time
intensive because the observers make there observations during at least 18 hours.
Moreover, the data is collected during a short period of time which means that the
information is not necessarily relevant for other periods of the year. This aspect should
be taking into account when designing a research and analysing the results. Because of
the fact that internationally different methods have been developed, it is very important
to define clearly what is meant with a conflict in order to be able to compare the results
with accident data and research results of other conflict observations. A third point of
interest has to do with the degree into which conflicts are an indication for the expected
level of unsafety. Serious conflicts can not simply be seen as an indicator for accidents,
but the can give an indication of the road safety of a certain location because patterns of
behaviour leading to conflicts can be detected.
Steunpunt Verkeersveiligheid 4 RA-2007-118