The effect of in-vehicle warning systems on speed compliance in work zones

報告者：楊子群

James Whitmire II a, , Justin F. Morgan, Tal Oron-Gilad c, P.A. Hancock ⇑

Goals and HypothesesGoals and Hypotheses Reference Method Results Discussion Conclusion

Research was to investigate the effectiveness of in-vehicle information technologies to 　 influence driver speed compliance in work zones.

Goals and Hypotheses Reference Method Results Discussion Conclusion

Reference

ParticipantsGoals and Hypotheses Reference Method Results Discussion Conclusion

60 participants (27 males, 33 females). Driver’s license with at least 3 years of driving experience. Age:20-63 years. Mean age:33 years, standard deviation:12years. Normal hearing and had normal or corrected to normal vision.

ApparatusGoals and Hypotheses Reference Method Results Discussion Conclusion

General Electric fixed-base, I-Sim Patrol Sim driving simulator(three flat screens)

National Instruments LabVIEWThis software, integrated with the simulator, recorded all information on the simulator network at a rate of 60 Hz / 每秒 60 次

(e.g., steering movement, brake and throttle inputs, and vehicle speed and position relative to other objects)Bluetooth wireless connection

HP IPaq hx4700 Pocket PCVisual warnings 0.5 s on and 0.5 s off.

Small speakerAuditory warningsMale’s voicePresented at 60 dbc

Experimental design and proceduresGoals and Hypotheses Reference Method Results Discussion Conclusion

8.9 km 2.1 km

40 khp105 khpStop sign One single right turn

Stop sign

7 min

Experimental design and proceduresGoals and Hypotheses Reference Method Results Discussion Conclusion

STEP1=> Participants were randomly assigned to one of the three stated levels.　　　　　　　　　　　　　　　　　　　　 (auditory, visual, or no warning)

STEP2=> informed consent process

STEP3=> filled out 1.simulation sickness questionnaire as a pre-screening device　　　　　　　 2.driving history questionnaire

STEP4=> given a scripted verbal overview of the simulator followed by a orientation drive.

STEP5=> pre-NASA-TLX

STEP6=> began the actual test drive(approximately 7 min)

STEP7=> post-experience instance of the simulation sickness questionnaire and NASA-TLX

Measures of driver responseGoals and Hypotheses Reference Method Results Discussion Conclusion

Speed before and within the work zone

Total time in work zone

Total time in violation

Number of violations

Duration of violations

Lane deviation, acceleration, braking, and steering

Subjective mental workload pre-post

Speed before and within the work zoneGoals and Hypotheses Reference Method Results Discussion Conclusion

pre-entry driving speeds, served to demonstrate that there were no significant

group 24 s mean 32 s mean post hoc comparisons

Control 56.8 kph 54.2 kph A

Visual 47.6 kph 43.3 kph B

Audio 40.7 kph 40.0 kph B

24 s and 32 s post-work zone seed have significant.

Total time in work zoneGoals and Hypotheses Reference Method Results Discussion Conclusion

Group Mean /s post hoc comparisons

Control 159.2 A

Visual 180.1 B

Audio 186.8 B

Analysis of variance revealed a marginal effect for total time in work zone F(2, 57) = 3.35, p = .08

Via Tukey’s procedure in a pairwise fashion:

Total time in violationGoals and Hypotheses Reference Method Results Discussion Conclusion

The results for total time in violation showed statistically significant differences, F(2, 57) = 5.05, p < .01.

post hoc comparisons with the use of the Dunnett’s C test:

Group Mean /s post hoc comparisons

Control 70.6(44%) A

Visual 32.3(18%) B

Audio 12.6(7%) B

Number of violationsGoals and Hypotheses Reference Method Results Discussion Conclusion

showed no significant differences between these respective violation levels (p > .25).

Duration of violationsGoals and Hypotheses Reference Method Results Discussion Conclusion

The ANOVA indicated significant differences F(2, 59) = 8.81, p = .0005.

Tukey-HSD revealed:Group Mean /s Post-compare

Control 25.7 A

Visual 8.9 B

Audio 3.3 B

Lane deviation, acceleration, braking, and steeringGoals and Hypotheses Reference Method Results Discussion Conclusion

lateral position following entrance into the work zone and subsequent vehicle position　 for the first 110 s of the test scenario.

No significant differences between observed measures.

Subjective mental workloadGoals and Hypotheses Reference Method Results Discussion Conclusion

(pre – post) measures were significantly different.1)Physical demand increased, t(19) = 2.82, p < .052)Effort increased, t(19) = 2.44, p < .053)Frustration decreased, t(19) = 3.52, p < .05

Goals and Hypotheses Reference Method Results Discussion Conclusion

Multimodal presentation of these types of messages to be clearly received by the driver, with only a minimal change in cognitive workload.

lack of other dynamic elements in the simulation as the driver traveled through the environment alone with no companion or on-coming traffic.

results confirm that the audio modality is an effective channel through which to cue the driver during a critical event.

results suggest there are indeed better ways to cue the driver to his or her speed within a work zone as compared to regular road signage

Goals and Hypotheses Reference Method Results Discussion Conclusion

Providing more efficient information communication to the driver will potentially prove most beneficial.

Driver message should begin with brief auditory and visual messages. (of duration no greater than a few seconds)

Followed by only a visual warning message which remains visible until compliance or acknowledgment.

In closing,further research is called for in the specific auditory and visual characteristics of such messages.