Recent evidence shows that drivers prefer a speed which is lower than the speed at which their subjective estimates of statistical risk begin to rise above zero. It also shows that up to this point, feelings of risk are completely decoupled (Author/publisher) from subjective statistical risk estimates. These results add further evidence against the 'target risk' concept which more -or-less equates statistical risk estimates with feelings of risk. In the context of safety motivation, if estimates of statistical risk do not provide the feedback in the control of driver decision-making, then what does? The Task-Capability Interface Model views driving as a control task in a dynamic system which constantly tends towards dis-equilibrium. It argues that it is task difficulty which provides the critical feedback in the decision-making loop. Task difficulty arises out of the transaction between current task demand and available driver capability and approximates what some other authors have referred to as 'workload'. Evidence shows that ratings of task difficulty, over a very wide range of speeds, are highly correlated with feelings of risk. Such feelings may provide the experiential feedback for managing task difficulty within acceptable boundaries. Thus what becomes important from a safety perspective is motivation for, or tolerance of, high levels of risk feeling.
Samenvatting