Characteristics of Drivers - Overtaking Maneuvers
Lunenfeld and Alexander (1990) consider the driving task to be a hierarchical process, with three levels:
(1) Control,
(2) Guidance, and
(3) Navigation.
The control level of performance comprises all those activities that involve second to-second exchange of information and control inputs between the driver and the vehicle. This level of performance is at the control interface. Most control activities, it is pointed out, are performed automatically, with little conscious effort.
The principal goal of the driver is to guide the vehicle from origin to destination in a safe manner. The driver may have some additional goals such as arriving at destination at the earliest possible time and the driver may also have certain goals concerning the environment through which the driver passes during the trip. At various points in the trip there may be special subtasks such as parking.
The task of accomplishing the driver's goals may be broken down into categories of action: perception, judgment, decision and control. The driver's control actions are limited to control of acceleration (braking and accelerating) and control of heading (steering or tracking). Overtaking is prone to many possible errors, not only because it is an event and not a continuous task, but also because it requires some special skills of the driver, e.g. judging the speed of an oncoming vehicle.