Objective metrics of comfort: Developing a driving style for highly automated vehicles

• In an on-road study objective metrics were found, which differentiate driving styles.
• A maneuver-based approach was used and confirmed.
• The identified metrics can be used to parametrize comfortable automated driving.
• Conclusions were drawn for highways as well as urban and rural roads.

This paper addresses the issue of enabling a comfortable highly automated driving style. Two studies have been conducted to identify metrics which can be used to parametrize a high-quality automated driving style for automobiles with regard to safety, functionality and comfort. The studies were set either in an urban and rural or a highway environment. Participants (N = 12 per study) manually drove a round course assuming either an everyday, a comfortable, or a dynamic driving style in randomized order. The obtained results emphasize the importance of maneuver-based analysis. Namely, a variety of maneuver-specific metrics, such as acceleration, jerk, quickness and headway distance in seconds, were identified, which are prerequisites to differentiate between the three driving styles. These metrics seem to be the essential components for the development of comfortable highly automated driving.