Tactical Decisions for Lane Changes or Lane Following: Assessment of Automated Driving Styles under Real-World Conditions

Automated vehicles offer various benefits for private transport. Besides an increase in road safety and driving comfort, higher levels of automated driving provide the opportunity to perform non-driving related tasks and to save time. Fundamental requirements for the success of automated driving are an appropriate tactical decision-making of the automation system and accepted automated driving styles. For this reason, this article focuses on the assessment of automated driving styles with different lane change frequencies and the potential influence of non-driving related tasks. A driving study (N = 60) was conducted on a German highway under real-world conditions using a vehicle with a prototype automation system. The evaluation of automated driving styles and driving experience of participants was based on well-being, driving comfort, trust in automation, and acceptance of the automation system. The study did not reveal any statistically significant interactions between three non-driving related tasks and two automated driving styles with a low and a high lane change frequency. However, the driving style with a low lane change frequency resulted in significantly more discomfort than the driving style with a high lane change frequency. Furthermore, the authors confirmed the assumption that intentions of an automated drive and external circumstances, such as time pressure or specific driving scenarios, affect the preferred lane change frequency.