SAfety VEhicles using adaptive Interface Technology (Task 4) Final Report Phase 2 Distraction Mitigation Evaluation

1、SAVE-ITSAfety VEhicles using adaptive Interface Technology (Task 4)Final Report: Phase 2Distraction Mitigation EvaluationPrepared byBirsen DonmezLinda N. BoyleJohn D. LeeThe University of IowaPhone: (319) 384-0810Email: February 2007Table of Contents TOC o 1-3 h z u HYPERLINK l _Toc160301267 4.1Exec

2、utive summary PAGEREF _Toc160301267 h 7 HYPERLINK l _Toc160301268 4.2Program Overview PAGEREF _Toc160301268 h 10 HYPERLINK l _Toc160301269 4.3Introduction and objectives PAGEREF _Toc160301269 h 11 HYPERLINK l _Toc160301270 4.4Designing feedback to mitigate distraction PAGEREF _Toc160301270 h 11 HYPE

3、RLINK l _Toc160301271 Feedback for distraction mitigation PAGEREF _Toc160301271 h 13 HYPERLINK l _Toc160301272 Timescales of feedback PAGEREF _Toc160301272 h 14 HYPERLINK l _Toc160301273 Concurrent feedback PAGEREF _Toc160301273 h 18 HYPERLINK l _Toc160301274 Delayed feedback PAGEREF _Toc160301274 h

4、 18 HYPERLINK l _Toc160301275 Post-hoc feedback PAGEREF _Toc160301275 h 20 HYPERLINK l _Toc160301276 Collective Feedback PAGEREF _Toc160301276 h 21 HYPERLINK l _Toc160301277 Combinations of different feedback timescales PAGEREF _Toc160301277 h 21 HYPERLINK l _Toc160301278 Interaction of feedback tim

5、ing and feedback content PAGEREF _Toc160301278 h 22 HYPERLINK l _Toc160301279 Conclusion PAGEREF _Toc160301279 h 24 HYPERLINK l _Toc160301280 4.5Drivers Attitudes towards imperfect distraction mitigation PAGEREF _Toc160301280 h 24 HYPERLINK l _Toc160301281 Focus groups to explore acceptance and trus

6、t PAGEREF _Toc160301281 h 26 HYPERLINK l _Toc160301282 Simulator experiments to assess acceptance and trust PAGEREF _Toc160301282 h 28 HYPERLINK l _Toc160301283 Methodology PAGEREF _Toc160301283 h 28 HYPERLINK l _Toc160301284 Participants PAGEREF _Toc160301284 h 28 HYPERLINK l _Toc160301285 Apparatu

7、s PAGEREF _Toc160301285 h 29 HYPERLINK l _Toc160301286 Experimental Design PAGEREF _Toc160301286 h 29 HYPERLINK l _Toc160301287 Procedure PAGEREF _Toc160301287 h 30 HYPERLINK l _Toc160301288 Dependent variables PAGEREF _Toc160301288 h 31 HYPERLINK l _Toc160301289 Results PAGEREF _Toc160301289 h 31 H

8、YPERLINK l _Toc160301290 Discussion PAGEREF _Toc160301290 h 34 HYPERLINK l _Toc160301291 4.6A realtime Index of visual distraction PAGEREF _Toc160301291 h 35 HYPERLINK l _Toc160301292 Methodology PAGEREF _Toc160301292 h 37 HYPERLINK l _Toc160301293 Participants PAGEREF _Toc160301293 h 37 HYPERLINK l

9、 _Toc160301294 Apparatus PAGEREF _Toc160301294 h 38 HYPERLINK l _Toc160301295 Driving task PAGEREF _Toc160301295 h 39 HYPERLINK l _Toc160301296 In-vehicle information system task PAGEREF _Toc160301296 h 39 HYPERLINK l _Toc160301297 Experimental design and independent variables PAGEREF _Toc160301297

10、h 40 HYPERLINK l _Toc160301298 Procedure PAGEREF _Toc160301298 h 40 HYPERLINK l _Toc160301299 Dependent variables PAGEREF _Toc160301299 h 40 HYPERLINK l _Toc160301300 Results PAGEREF _Toc160301300 h 41 HYPERLINK l _Toc160301301 Discussion PAGEREF _Toc160301301 h 45 HYPERLINK l _Toc160301302 4.7Concu

11、rrent feedback to Mitigate Distraction PAGEREF _Toc160301302 h 47 HYPERLINK l _Toc160301303 Methods PAGEREF _Toc160301303 h 49 HYPERLINK l _Toc160301304 Participants PAGEREF _Toc160301304 h 49 HYPERLINK l _Toc160301305 Apparatus PAGEREF _Toc160301305 h 49 HYPERLINK l _Toc160301306 Driving task PAGER

12、EF _Toc160301306 h 50 HYPERLINK l _Toc160301307 In-vehicle information system task PAGEREF _Toc160301307 h 50 HYPERLINK l _Toc160301308 Experimental design and independent variables PAGEREF _Toc160301308 h 51 HYPERLINK l _Toc160301309 Dependent variables PAGEREF _Toc160301309 h 51 HYPERLINK l _Toc16

13、0301310 Results PAGEREF _Toc160301310 h 53 HYPERLINK l _Toc160301311 Discussion PAGEREF _Toc160301311 h 60 HYPERLINK l _Toc160301312 4.8feedback at different timescales: Concurrent and post-Hoc Feedback PAGEREF _Toc160301312 h 62 HYPERLINK l _Toc160301313 Methods PAGEREF _Toc160301313 h 63 HYPERLINK

14、 l _Toc160301314 Participants PAGEREF _Toc160301314 h 63 HYPERLINK l _Toc160301315 Apparatus PAGEREF _Toc160301315 h 63 HYPERLINK l _Toc160301316 Driving Task PAGEREF _Toc160301316 h 64 HYPERLINK l _Toc160301317 Experimental design and independent variables PAGEREF _Toc160301317 h 64 HYPERLINK l _To

15、c160301318 Procedure PAGEREF _Toc160301318 h 66 HYPERLINK l _Toc160301319 Dependent Variables PAGEREF _Toc160301319 h 66 HYPERLINK l _Toc160301320 Results PAGEREF _Toc160301320 h 67 HYPERLINK l _Toc160301321 Response to lead vehicle braking PAGEREF _Toc160301321 h 67 HYPERLINK l _Toc160301322 Intera

16、ction with in-vehicle display: Eye movements and button presses PAGEREF _Toc160301322 h 72 HYPERLINK l _Toc160301323 Subjective measures PAGEREF _Toc160301323 h 75 HYPERLINK l _Toc160301324 Discussion PAGEREF _Toc160301324 h 79 HYPERLINK l _Toc160301325 4.9References PAGEREF _Toc160301325 h 80Table

17、of Figures TOC h z c Figure 4. HYPERLINK l _Toc160355579 Figure 4. 1. Levels of feedback timing and the magnitude of targeted influence (indicated by arrow stroke width). PAGEREF _Toc160355579 h 13 HYPERLINK l _Toc160355580 Figure 4. 2. The process by which a driver responds to feedback at different

18、 timescales. PAGEREF _Toc160355580 h 14 HYPERLINK l _Toc160355581 Figure 4. 3. The visual advising strategy. PAGEREF _Toc160355581 h 30 HYPERLINK l _Toc160355582 Figure 4. 4. Acceptance of mitigation strategies by age group and presentation modality. PAGEREF _Toc160355582 h 32 HYPERLINK l _Toc160355

19、583 Figure 4. 5. Trust on mitigation strategies by system adaptation, age group, and presentation modality. PAGEREF _Toc160355583 h 33 HYPERLINK l _Toc160355584 Figure 4. 6. Acceptance of mitigation strategies embedded in current in-vehicle systems PAGEREF _Toc160355584 h 34 HYPERLINK l _Toc16035558

20、5 Figure 4. 7. In-vehicle display, road scene and eye-tracking cameras PAGEREF _Toc160355585 h 38 HYPERLINK l _Toc160355586 Figure 4. 8. In-vehicle task displayed on the LCD monitor PAGEREF _Toc160355586 h 40 HYPERLINK l _Toc160355587 Figure 4. 9. Accelerator release time and transition times for di

21、fferent experimental conditions and risk levels PAGEREF _Toc160355587 h 42 HYPERLINK l _Toc160355588 Figure 4. 10. Minimum acceleration for different experimental conditions and risk levels PAGEREF _Toc160355588 h 43 HYPERLINK l _Toc160355589 Figure 4. 11 Duration of glances on the in-vehicle displa

22、y for risky and non-risky driver categories PAGEREF _Toc160355589 h 44 HYPERLINK l _Toc160355590 Figure 4. 12. Number of alarms for different alarm thresholds for different risk levels PAGEREF _Toc160355590 h 45 HYPERLINK l _Toc160355591 Figure 4. 13. Acceptance of mitigation strategies by age group

23、 and presentation modality. PAGEREF _Toc160355591 h 52 HYPERLINK l _Toc160355592 Figure 4. 14. Estimated means and 95% confidence intervals for curve negotiation measures: (a) curve entry speed and (b) steering entropy. PAGEREF _Toc160355592 h 55 HYPERLINK l _Toc160355593 Figure 4. 15. Estimated mea

24、ns and 95% confidence intervals for lead vehicle braking event response measures: (a) Speed when lead vehicle starts to brake (b) Accelerator release time (c) Minimum acceleration (negative maximum deceleration) (d) Minimum time to collision for each condition. PAGEREF _Toc160355593 h 56 HYPERLINK l

25、 _Toc160355594 Figure 4. 16. Estimated means and 95% confidence intervals for (a) number of glances (per minute) on the in-vehicle display and (b) mean duration of roadway-glances. PAGEREF _Toc160355594 h 57 HYPERLINK l _Toc160355595 Figure 4. 17. Estimated mean glance duration (and 95% confidence i

26、nterval) on the in-vehicle display after (a) is exceeded and (b) is exceeded. PAGEREF _Toc160355595 h 58 HYPERLINK l _Toc160355596 Figure 4. 18. Subjective responses (estimated means and 95% confidence intervals) for (a) perceived risk, (b) mental effort, and (c) acceptance of distraction-feedback.

27、PAGEREF _Toc160355596 h 59 HYPERLINK l _Toc160355597 Figure 4. 19. Trip-report (a) positive feedback for no incidents (b) overview when there are incidents (c) detailed information on the incident PAGEREF _Toc160355597 h 65 HYPERLINK l _Toc160355598 Figure 4. 20. Incident visualization: (a) speeding

28、, (b) too close to lead vehicle, (c) lane deviation, (d) collision with lead vehicle, (e) collision with oncoming vehicle PAGEREF _Toc160355598 h 66 HYPERLINK l _Toc160355599 Figure 4. 21. Reaction to lead vehicle braking events (estimated means and standard error bars) (a) accelerator release time

29、(b) brake reaction time PAGEREF _Toc160355599 h 70 HYPERLINK l _Toc160355600 Figure 4. 22. Safety outcomes for lead vehicle braking event response (estimated means and standard error bars) (a) minimum TTC (b) minimum acceleration PAGEREF _Toc160355600 h 71 HYPERLINK l _Toc160355601 Figure 4. 23. Eye

30、-movements (estimated means and standard error bars) (a) number of glances per minute on in-vehicle display (b) glance duration on in-vehicle display (c) glance duration on the road PAGEREF _Toc160355601 h 73 HYPERLINK l _Toc160355602 Figure 4. 24. Number of button presses per minute (estimated mean

31、s and standard error bars) PAGEREF _Toc160355602 h 75 HYPERLINK l _Toc160355603 Figure 4. 25. Subjective measures (estimated means and standard error bars) (a) perceived risk (b) mental effort PAGEREF _Toc160355603 h 76 HYPERLINK l _Toc160355604 Figure 4. 26. Acceptance of feedback (estimated means

32、and 95% confidence intervals). PAGEREF _Toc160355604 h 78Table of Tables TOC h z c Table 4. HYPERLINK l _Toc160304991 Table 4. 1. Taxonomy of distraction mitigation strategies (Phase 1). PAGEREF _Toc160304991 h 7 HYPERLINK l _Toc160304992 Table 4. 2. Potential pros and cons for different feedback ti

33、mescales. PAGEREF _Toc160304992 h 16 HYPERLINK l _Toc160304993 Table 4. 3. Taxonomy of distraction mitigation strategies. PAGEREF _Toc160304993 h 27 HYPERLINK l _Toc160304994 Table 4. 4. Decrement in accelerator release time from the non-distracted to the distracted condition. PAGEREF _Toc160304994

34、h 42 HYPERLINK l _Toc160304995 Table 4. 5. Analyses of variance (F-tests) for braking response. PAGEREF _Toc160304995 h 53 HYPERLINK l _Toc160304996 Table 4. 6. Analyses of variance (F-tests) for eye-movements. PAGEREF _Toc160304996 h 54 HYPERLINK l _Toc160304997 Table 4. 7. Analyses of variance (F-

35、tests) for questionnaire responses. PAGEREF _Toc160304997 h 54 HYPERLINK l _Toc160304998 Table 4. 8. Subjective responses to whether or not performance of feedback enhanced their driving performance. PAGEREF _Toc160304998 h 60 HYPERLINK l _Toc160304999 Table 4. 9. Incident severity levels. PAGEREF _

36、Toc160304999 h 65 HYPERLINK l _Toc160305000 Table 4. 10. Significant pair-wise comparisons for lead vehicle braking response. PAGEREF _Toc160305000 h 68 HYPERLINK l _Toc160305001 Table 4. 11. Significant pair-wise comparisons for interaction with in-vehicle display. PAGEREF _Toc160305001 h 74 HYPERL

37、INK l _Toc160305002 Table 4. 12. Significant pair-wise comparisons for subjective measures. PAGEREF _Toc160305002 h 77 HYPERLINK l _Toc160305003 Table 4. 13. Subjective responses relating to driving performance. PAGEREF _Toc160305003 h 79Executive summaryThe objective of Task 4 (Distraction Mitigati

38、on) is to develop countermeasures that mitigate distraction in a way that drivers find acceptable. In Phase 1, a literature review was conducted that generated a taxonomy of distraction mitigation strategies ( REF _Ref160301919 h Table 4. 1) ADDIN EN.CITE Donmez200365577Donmez, B.Boyle, L.,Lee, J. D

39、.2003Taxonomy of mitigation strategies for driver distractionHuman Factors and Ergonomics Society 47th Annual MeetingSanta Monica, CAHuman Factors and Ergonomics Society1865-1869(Donmez, Boyle, & Lee, 2003). This taxonomy provided a classification scheme based on dimensions identified as particularl

40、y relevant to distraction mitigationautomation, initiation type, and the task being modulated by the strategy. Second, the classification helped identify current gaps in research and areas where additional strategies were needed. Focus groups were then conducted to assess drivers acceptance of and t

41、rust in all the strategies (existing and innovative) as defined in the taxonomy. A driving simulator study was conducted to further assess the effectiveness, acceptance, and trust of two of the more promising strategies: an advising strategy that warns drivers of roadway events and a locking strateg

42、y that prevents the driver from continuing a distracting task during a roadway event ADDIN EN.CITE Donmez200675820Donmez, B.Boyle, L. N.Lee, J. D.2006Drivers' attitudes toward imperfect distraction mitigation strategiesTransportation Research Part F: Traffic Psychology96387-398JournalDonmez2006

43、75810Donmez, B.Boyle, L. N.Lee, J. D.2006The impact of driver distraction mitigation strategies on driving performanceHuman Factors484785-804Journal(Donmez, Boyle, & Lee, 2006a, 2006b). Table 4. SEQ Table_4. * ARABIC 1. Taxonomy of distraction mitigation strategies (Phase 1).LEVEL OF AUTOMATIONDRIVI

44、NG RELATED STRATEGIESNON DRIVING RELATED STRATEGIESSystem InitiatedDriver InitiatedSystem InitiatedDriver InitiatedHighInterveningDelegatingLocking & InterruptingControls PresettingModerateWarningWarning TailoringPrioritizing & FilteringPlace-keepingLowInforming Perception AugmentingAdvisingDemand M

45、inimizingIn the second phase of this project the taxonomy in REF _Ref160301919 h Table 4. 1 was extended by considering how mitigation might be used to provide drivers with feedback at different timescales. REF _Ref160355892 h Figure 4. 1 shows how such feedback might not only mitigate the effects a

46、ssociated with the immediate driving performance impairment that distraction can cause, but feedback can also mitigate distraction by introducing long-term changes in driver behavior. A specific example of this feedback includes post-hoc feedback that the driver might receive at the end of the drive

47、.Figure 4. SEQ Figure_4. * ARABIC 1. Feedback at different timescales as strategies to mitigate distraction.Several experiments have evaluated the strategies identified in REF _Ref160301919 h Table 4. 1 and REF _Ref160355892 h Figure 4. 1. The first of these included two age groups: old (65-75) and

48、middle-aged (35-55) and investigated the effects of two modalities (visual and auditory). Visual modality was implemented as a red bezel on the in-vehicle display. Auditory modality was implemented as a background clicking sound. Interestingly, the focus group and the experimental findings suggest t

49、hat older drivers accepted and trusted the strategies more than middle-aged drivers. Regardless of age, all drivers preferred strategies that provided alerts in a visual mode rather than an auditory mode. When the system falsely adapted to the road situation, trust in the strategies declined. The fi

50、ndings show that display modality has a strong effect on driver acceptance and trust, and that older drivers are more trusting and accepting of distraction mitigation technology even when it operates imperfectly. In terms of driving performance measures, distraction was a problem for both age groups

51、. Visual distractions were more detrimental than auditory ones for curve negotiation as reflected by more erratic steering. Drivers did brake more abruptly under auditory distractions, but this effect was mitigated by both the advising and locking strategies. Regardless of drivers age, both strategi

52、es resulted in longer minimum time-to-collision under auditory distractions. The locking strategy also resulted in longer minimum time-to-collision for middle-aged drivers engaged in visual distractions. A disadvantage of these strategies, when based on roadway events, is the inability to effectivel

53、y warn drivers of prolonged engagement in the IVIS. Some distractions may degrade driving performance to safety critical levels even on straight roads with low levels of traffic. Providing feedback when the driver is highly distracted can help avoid future hazardous maneuvers. Another disadvantage o

54、f mitigation strategies based only on the roadway state concerns non-useful alarms. Although there is a roadway event, such as a curve, the driver may actually be focused on the driving task and be able to respond quite appropriately. An alarm provided in this situation can degrade system acceptance

55、 and result in frustration, which itself is a type of distraction that can have a negative effect on traffic safety ADDIN EN.CITE Burns2000758816Burns, P. C.Lansdown, T. C.2000 E-distraction: the challenges for safe and usable internet services in /departments/nrd-13/dri

56、ver-distraction/Topics043100029.htm2004July(Burns & Lansdown, 2000). This can be avoided by giving drivers feedback based on their attentional state rather than just the roadway state. Moreover, compared to warnings based on roadway events, which can have an impact on immediate performance, feedback

57、 on drivers engagement in distractions can generate a long-term behavioral change. To support warnings based on driver state, an experiment was conducted to develop an algorithm to identify risky visual scanning patterns. The algorithm defined the degree of distraction as a function of the current o

58、ff-road glance duration, 1, and the total off-road glance duration during the last 3 sec, 2, with the relative influence of the current glance duration as A 3 sec moving average of glance duration has been shown to predict distraction ADDIN EN.CITE Zhang2004761516Zhang, H. M. Smith.2004A Final Repor

59、t of SAfety Vehicles using adaptive Interface Technology (Phase I: Task 7): Visual Distraction Research :/ /opsad/saveit/docs/dec04/finalrep_7b.pdf.2005January(Zhang & Smith., 2004). These factors then defined a momentary value of distraction, for the algorithm:.This algorithm was used

60、in a subsequent driving simulator study which was conducted to assess whether real-time feedback on a drivers state can influence the drivers interaction with in-vehicle information systems (IVIS). A driving simulator experiment was designed to test real-time feedback that alerts drivers based on th