Transcript The effect of in

The effect of in-vehicle warning systems
on speed compliance in work zones
James Whitmire II a,⇑, Justin F. Morgan, Tal Oron-Gilad c, P.A. Hancock
Goals and Hypotheses
Reference
Method
Results
Discussion
Conclusion
Goals and Hypotheses
 Research was to investigate the effectiveness of in-vehicle information technologies to
influence driver speed compliance in work zones.
Goals and Hypotheses
Reference
Method
Reference
Results
Discussion
Conclusion
Goals and Hypotheses
Reference
Method
Results
Participants
 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.
Discussion
Conclusion
Goals and Hypotheses
Reference
Method
Results
Discussion
Conclusion
Apparatus
General Electric fixed-base, I-Sim Patrol Sim driving simulator(three flat screens)
National Instruments LabVIEW
This software, integrated with the simulator, recorded all information on the simulator network at a rate of 60 Hz
(e.g., steering movement, brake and throttle inputs, and vehicle speed and position relative to other objects)
Bluetooth wireless connection
HP IPaq hx4700 Pocket PC
Visual warnings
0.5 s on and 0.5 s off.
Small speaker
Auditory warnings
Male’s voice
Presented at 60 dbc
/每秒60次
Goals and Hypotheses
Reference
Method
Results
Discussion
Conclusion
Experimental design and procedures
8.9 km
2.1 km
105 khp
40 khp
Stop sign
One single right turn
7 min
Stop sign
Goals and Hypotheses
Reference
Method
Results
Discussion
Conclusion
Experimental design and procedures
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
Goals and Hypotheses
Reference
Method
Results
Measures of driver response
 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
Discussion
Conclusion
Goals and Hypotheses
Reference
Method
Results
Discussion
Conclusion
Speed before and within the work zone
pre-entry driving speeds, served to demonstrate that there were no significant
24 s and 32 s post-work zone seed have significant.
group
24 s mean
32 s mean
post hoc comparisons
Control
56.8 kph
54.2 kph
Visual
47.6 kph
43.3 kph
B
Audio
40.7 kph
40.0 kph
B
A
Goals and Hypotheses
Reference
Method
Results
Discussion
Conclusion
Total time in work zone
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:
Group
Mean /s
post hoc comparisons
Control
159.2
Visual
180.1
B
Audio
186.8
B
A
Goals and Hypotheses
Reference
Method
Results
Discussion
Total time in violation
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%)
Visual
32.3(18%)
B
Audio
12.6(7%)
B
A
Conclusion
Goals and Hypotheses
Reference
Method
Results
Discussion
Conclusion
Number of violations
showed no significant differences between these respective violation levels (p > .25).
Goals and Hypotheses
Reference
Method
Results
Discussion
Conclusion
Duration of violations
The ANOVA indicated significant differences F(2, 59) = 8.81, p = .0005.
Tukey-HSD revealed:
Group
Mean /s
Post-compare
Control
25.7
Visual
8.9
B
Audio
3.3
B
A
Goals and Hypotheses
Reference
Method
Results
Discussion
Conclusion
Lane deviation, acceleration, braking, and steering
 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.
Goals and Hypotheses
Reference
Method
Results
Subjective mental workload
(pre – post) measures were significantly different.
1) Physical demand increased, t(19) = 2.82, p < .05
2) Effort increased, t(19) = 2.44, p < .05
3) Frustration decreased, t(19) = 3.52, p < .05
Discussion
Conclusion
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.