1. Situation awareness and driving performance in a simulated navigation task Author: R. MA and D. B. Kaber Ergonomics (2007)

2. Introduction Driving is considered to be a complex task requiring perception, comprehension and projection of states of the roadway environment Situation awareness (SA) encompasses three of these aspects of driving performance and has been found to be critical to decision making in complex tasks (Endsley 1995a).

3. Introduction Gugerty & Tirre (2000) 認為汽車駕駛有以 下四類情境知覺： (1) 導航知覺 (Navigation knowledge) (2) 區域場景知覺 (Local scene comprehension) (3) 空間方向 知覺 (Knowledge of spatial orientation) (4) 汽車狀態知覺 (Knowledge of vehicles status) 。 Gugerty & Tirre (2000) 認為汽車駕駛有以 下四類情境知覺： (1) 導航知覺 (Navigation knowledge) (2) 區域場景知覺 (Local scene comprehension) (3) 空間方向 知覺 (Knowledge of spatial orientation) (4) 汽車狀態知覺 (Knowledge of vehicles status) 。

4. Introduction 第一階段 (Level 1 SA) ：察覺環境中關鍵 的元素。 第一階段 (Level 1 SA) ：察覺環境中關鍵 的元素。 (2) 第二階段 (Level 2 SA) ：理解這些環境 元素代表的意義，包括質與量。 (2) 第二階段 (Level 2 SA) ：理解這些環境 元素代表的意義，包括質與量。 (3) 第三階段 (Level 3 SA) ：針對感知環境 中的元素進行未來狀態變動的預測。 (3) 第三階段 (Level 3 SA) ：針對感知環境 中的元素進行未來狀態變動的預測。

5. Introduction Ma and Kaber (2005) investigated the effects of adaptive cruise control (ACC – see also Stanton and Young 2005) and mobile phone use on driver SA and performance in a lead-car following task primarily involving operational behaviours. – –They also found significant positive correlations between SA and aspects of driving performance

6. Objects The objectives of the current research were to investigate the potential mediating effect of in-vehicle navigation aids and aid reliability on the relationship of driver SA (at multiple levels) with performance in a strategic driving and navigation task.

7. Experiment Task Task –This study used a ‘ home-grown ’ virtual reality-based driving simulator –There were three construction sites on the suburb roadways and participants were required to make five or more turns to navigate the sites and reach the destination –There were different types of traffic signs including ‘ speed limit ’ (30 or 45 mph) speed limit ’ (30 or 45 mph) ‘ stop ’ signs ‘ stop ’ signs street name signs street name signs

10. Experiment Half of the participants received navigation instructions from a remote experimenter via a Motorola T720 mobile phone Half of the participants received navigation instructions from a remote experimenter via a Motorola T720 mobile phone Other participants received navigation information from an automated aid presented on an IBM laptop placed directly adjacent to the primary virtual reality simulation display Other participants received navigation information from an automated aid presented on an IBM laptop placed directly adjacent to the primary virtual reality simulation display In all navigation trials, participants had a paper map, which showed the entire suburb navigation area In all navigation trials, participants had a paper map, which showed the entire suburb navigation area

11. Experiment Variables Variables –navigation aid type (i.e. human or automation), between-subjects –level of navigation aid reliability manipulated (100%, 80% and 60% reliable conditions)as a within-subjects The navigation aiding provided drivers with turning information (street names) and speed limit information. All of the information was correct according to the street signage The navigation aiding provided drivers with turning information (street names) and speed limit information. All of the information was correct according to the street signage

12. Experiment Reliable Reliable –The 100% reliable navigation condition required drivers to make five turns and they spent an average of 11.7 min in reaching the destination from the freeway exit. –The 80% reliable navigation condition required drivers to make six turns and average navigation time was 14.2 min. –The 60% reliable navigation condition required seven turns and an average driving time of 15.1 min.

13. Experiment Reliable Reliable –Telemarketing survey the paper copy of the map was marked with an optimal route for navigation The telemarketing survey was communicated by the human through the mobile phone or by the automation aid through the laptop display

14. Experiment Dependent variables Dependent variables –driving performance (the number of errors drivers; speed control) –Driver SA was assessed at the end of each trial using an adaptation of the SA global assessment technique (SAGAT; Endsley 1995b)

15. Experiment- SAGAT

18. Participants and procedures A total of 20 students they were required to have at least 3 years of driving experience to participate. The average age of participants was 28.1 years and the sample had an average of 8.5 years of driving experience

19. Participants and procedures Training () Training (very much like that of a real vehicle) Wizard-of-oz technique was used Wizard-of-oz technique was used

20. Results Driving performance Driving performance F(3,79)=5.00, P<0.01 F(3,79)=3.49, P<0.02

21. Results Driver situation awareness Driver situation awareness F(3,79)=7.19, P<0.01 F(3,79)=16.78, P<0.01 F(3,79)=3.17, P<0.05

22. Results A Pearson coefficient revealed a significant negative linear association between Level 3 SA scores and driving navigation errors (r=-0.25, p<0.05) (Matthews et al., 2001)

23. Discussion The automation aid in this study demanded driver visual attention (Ho et al. 2006) for perception of navigation information. Since driving is a visual and motor control process, it is possible that the visual search demands associated with retrieving information from the automation-aid display also degraded driver SA

24. Discussion Driver Level 1 SA was particularly low under the perfect aiding condition. they did not pay as much attention to observing aspects of the roadway This potential behaviour was also evidenced in comparison to the 80% and 60% reliable aiding results. Participants appeared to pay close attention to the driving environment when they were provided with imperfect aiding

25. Discussion there were no significant differences in SA among the aid types; however, SA accuracy across all reliability levels was far from perfect some other research has provided evidence that mobile phone use, while driving, significantly degrades SA, particularly Levels 2 and 3 (Gugerty et al. 2003, Ma 2006, Ma and Kaber 2005).

26. Discussion these results revealed that higher aid reliability produced higher driver SA (Levels 2, 3 and overall SA).

27. Discussion driving behaviours to the three levels of SA it appears that driver SA was significantly affected by aid reliability, and driver performance was significantly correlated with changes in high level SA Ma and Kaber (2005), revealed positive associations between SA with one or more dimensions of driving performance.