An Examination of Overtaking Judgments Based on Limitations in the Human Perceptual System: Implications for the Design of Driver-Assistance Systems - Digital Signal Processing for In-Vehicle Systems and Safety - page 230

However, an overtaking maneuver can take up to 6 s [ 22 ], and prior research shows
that the accuracy of TTC judgments decreases as the actual TTC increases [ 17 ].
In sum, the typical functional requirements and thresholds considered in the design
of FCAWS to aid safe car following cannot be generalized to aid overtaking
maneuvers. Therefore, as an aid to overtaking maneuvers, DAS needs a separate
set of functional requirements and thresholds.
17.4 Driver-Assistance Warning Systems
for Overtaking Maneuvers
In this section, I identify seven functional requirements that have to be considered
as guidelines while designing DAS to support overtaking maneuvers. Importantly,
the requirements have been developed to overcome the perceptual limitations of
drivers while carrying out overtaking maneuvers. Also, the human factor involved
in such a human-automation interaction is considered.
17.4.1 Focus on Object-Motion Processing in Addition
to Object Recognition
Most rear-end collisions occur when the driver is distracted and does not view the
traffic for adequate amount of time [ 40 ]. Therefore, forward-collision-avoidance-
warning-systems designed to support safe car following typically focus on object
recognition because it assumes that the driver is not attentive to the traffic scene.
However, during an overtaking maneuver, the drivers typically have their eyes on
the road throughout the maneuver and hence are attending to the traffic scene.
Under such conditions, it is the incapability of the human perceptual system to
perceive distance and motion that leads to inaccurate judgments rather than a lack
of attention to the traffic scene. Therefore, the DAS should be developed to
overcome such limitations.
17.4.2 Capability to Detect the Motion Parameters of a Vehicle
at Far Distances from the Self
Human perceptual system is typically incapable of accurately detecting a vehicle's
motion when its distance from the self is very far. However, overtaking maneuvers
might have to be performed at such distances (e.g., 200 m).