In my PhD thesis from 1996, I developed a model of driver behaviour that was named the adaptation model of car driving. In this article I will present the outline of the model. In the thesis, a number of experiments were presented that were designed to test important elements of the model. All experiments were performed in a research car driving simulator and most of the studies were published in the scientific literature.
The main element of the adaptation model of driver behaviour is that it predicts that any factor that affects operational performance will
- normally result in an adaptation of behaviour on the tactical level,
- such that constant safety margins are maintained.
The model represented in the following figure.
This model states that several
factors affect operational performance. For example, temporary states, induced
by alcohol or marijuana, affect psycho-motor abilities while psycho-motor
abilities affect operational performance. Also, vehicle related factors, situational factors and driving experience may affect operational performance
in accordance with the adaptive control models. The effects on operational
performance are perceived via a feedback loop by the driver, although alcohol
and young age may inhibit this.
If driving is self-paced, the driver adjusts
behaviour on the tactical level by either increasing speed or decreasing
headway during car-following if operational performance is improved, or by
decreasing speed or increasing headway if operational performance deteriorates.
If there are no opportunities to adapt behaviour on the tactical level, i.e.
when the driving task is forced-paced, the driver may elect in allocate more
effort to increase operational performance.
Adaptation of tactical behaviour or
effort allocation does not only occur as a response to momentary changes, but
also in the form of an anticipatory response. This response is the result of
learned associations between various factors and effects on operational
performance allowing an adaptation of tactical behaviour in the absence of an
effect on operational performance. For example, if the driver has learned the
effects of rain on road friction and on operational steering performance, he
may already choose a lower speed before these effects are actually experienced
during a particular period of rain.
When drivers are not able to adapt behaviour on the tactical level for whatever reason, for example,
the risk of traffic accidents greatly increases. So the model has a direct link with driver safety. It also explains why vehicle factors aimed to improve safety often don't result in safety improvements in practice.
The complete thesis can be downloaded here.
When drivers are not able to adapt behaviour on the tactical level for whatever reason, for example,
- because they are intoxicated with alcohol or drugs or
- impaired by fatigue or drowsiness, or
- because they are inexperienced, or they overestimate their driving skills,
the risk of traffic accidents greatly increases. So the model has a direct link with driver safety. It also explains why vehicle factors aimed to improve safety often don't result in safety improvements in practice.
The complete thesis can be downloaded here.
No comments:
Post a Comment