## 4 Results  
### Comfort and Safety Perception of Experienced Automated Driving Style  
A total of 2.544 situations were rated during the automated drive. The vast majority of situations were rated positively with values greater than zero. Specifically, 83.73% regarding comfort and 91.75% regarding safety. Ratings with a scale value of 3 represent the highest proportion of all ratings with 55.19% for comfort and 68.32% for safety. Of all situations, 7.11% were rated neutral in terms of comfort and 3.58% in terms of safety. Negative ratings account for a total of 9.16% for comfort and 4.68% for safety. The participants' PDS includes all types of DS from very defensive to very aggressive. In total, there are 4 participants with a very defensive, 21 with a defensive and 14 participants with a moderate DS. Two participants show an aggressive and one participant a very aggressive DS. Figure 2b shows the resulting DS values for PDS, DDS, and ASD of each participant. The participants are listed in ascending order based on their PDS. The artificial very defensive driver has ID 0, and the artificial very aggressive driver has ID 43. For the self-reported driving style from the driver's perspective, the values tend to be closer to the rating pole calm/balanced (M = 2.62, SD = 1.02). The values for the self-reported DS from a co-pilot's perspective are significantly higher (M = 2.90, SD = 1.09, \(t\) = \(-\)2.75, \(p\) = 0.009). For comparison of both self-reported DS, a paired \(t\)-test was used. The DS values show a high correlation with both the self-reported DS from the driver's perspective (\(t\) = 0.49, \(p\) < 0.001) and from a co-driver's perspective (\(t\) = 0.45, \(p\) < 0.001). Figure 2a shows the resulting PDS over both self-reported DS. The ADS ranges between 0.13 and 0.23 with a mean value of M = 0.18 (SD = 0.03). Hence, the similarity threshold defining a similar to equal DS results in \(ST\) = \(\pm\)0.16 by using Equation (3). Based on this threshold and the driving style differences from Equation (2),23 participants with a DS ranging from 0.09 to 0.38 experienced an ADS similar or equal to their PDS. A total of 19 participants with a DS ranging from 0.30 to 0.89 experienced an ADS that is more defensive than their PDS. Due to the defensive to very defensive DS of the AV, no participant experienced an ADS that was more aggressive than their PDS. Prior to performing a group comparison for comfort and safety, the data were checked for a correlation to see if a general relationship between the DS differences and ratings existed. The DS differences show a significant correlation with comfort (\(\tau=0.09\), \(p<0.001\)) but no significant correlation with safety (\(\tau=0.00\), \(p=0.982\)). Therefore, a group comparison was performed between the groups DS\({}_{\text{mdef}}\) and DS\({}_{\text{eq}}\) with regard to comfort, as shown in Figure 3a. Since only two groups result from categorization, no Bonferroni-Holm correction is applied. Participants in group DS\({}_{\text{eq}}\) show a higher comfort rating (M = 2.26, SD = 1.17) than participants of group DS\({}_{\text{mdef}}\) (M = 1.83, SD = 1.57, \(U=892226.5\), \(p<0.001\)). The participants' PDS (M = 0.38, SD = 0.16) and DDS (M = 0.36, SD = 0.15) show no significant difference (\(t=1.11\), \(p=0.272\)). Figure 3b shows the value range of both driving styles. Figure 3: (**a**) Comparison of comfort ratings between participants who experienced a more defensive ADS compared to their PDS (DS\({}_{\text{mdef}}\)) and participants who experienced an ADS similar or equal to their PDS (DS\({}_{\text{eq}}\)). (**b**) Comparison between participants’ personal (PDS) and desired (DDS) driving style. Figure 2: (**a**) Comparison of self-reported DS from the driver’s perspective and from a co-driver’s perspective with the calculated personal driving style (PDS) values. The endpoles 1 and 5 on the x-axis represent a calm/balanced and sporty/dynamic driving style, respectively.