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

Goals and HypothesesReferenceMethodResultsDiscussionConclusion Reference

Participants Goals and HypothesesReferenceMethodResultsDiscussionConclusion  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.

Apparatus Goals and HypothesesReferenceMethodResultsDiscussionConclusion  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 / 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 PC Visual warnings 0.5 s on and 0.5 s off.  Small speaker Auditory warnings Male’s voice Presented at 60 dbc

Experimental design and procedures Goals and HypothesesReferenceMethodResultsDiscussionConclusion 8.9 km2.1 km 40 khp105 khp  Stop sign  One single right turn Stop sign 7 min

Experimental design and procedures Goals and HypothesesReferenceMethodResultsDiscussionConclusion 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 response Goals and HypothesesReferenceMethodResultsDiscussionConclusion  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 zone Goals and HypothesesReferenceMethodResultsDiscussionConclusion  pre-entry driving speeds, served to demonstrate that there were no significant group24 s mean32 s meanpost hoc comparisons Control56.8 kph54.2 kph A Visual47.6 kph43.3 kphB Audio40.7 kph40.0 kphB  24 s and 32 s post-work zone seed have significant.

Total time in work zone Goals and HypothesesReferenceMethodResultsDiscussionConclusion GroupMean /spost hoc comparisons Control159.2 A Visual180.1B Audio186.8B 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 violation Goals and HypothesesReferenceMethodResultsDiscussionConclusion 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: GroupMean /spost hoc comparisons Control70.6(44%) A Visual32.3(18%)B Audio12.6(7%)B

Number of violations Goals and HypothesesReferenceMethodResultsDiscussionConclusion showed no significant differences between these respective violation levels (p >.25).

Duration of violations Goals and HypothesesReferenceMethodResultsDiscussionConclusion The ANOVA indicated significant differences F(2, 59) = 8.81, p = Tukey-HSD revealed: GroupMean /sPost-compare Control25.7 A Visual8.9B Audio3.3B

Lane deviation, acceleration, braking, and steering Goals and HypothesesReferenceMethodResultsDiscussionConclusion  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 workload Goals and HypothesesReferenceMethodResultsDiscussionConclusion  (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

Goals and HypothesesReferenceMethodResultsDiscussionConclusion  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 HypothesesReferenceMethodResultsDiscussionConclusion  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.