an investigation of road crossing in a virtual environment student :董瑩蟬
TRANSCRIPT
An investigation of road crossing in a virtual
environment
Student:董瑩蟬
Purpose
This study employed a virtual
reality ,which is investigation
children and young adults on the
road crossing behavior.
Reference年份 學者 研究結果
1981-1996
Height et al.
Connelly et al.
Pedestrian death and serious injury to young children is the most common causes.
1983-2000
Jonah et al.
Land et al.
The highest Pedestrian deaths is 15-19 years have 17%, fellow this 75-79have 14% 5-9 and10-14 have 3%
1991 Thomson This have been identified Young children road crossing
1993-2000
Demetre et al.
Pitcairn et al.
Young children to be worse at making safe road crossing decisions than older child and adults
Method1.Participants
Total 24 people , range 5~30 years
Age group 5-9、 10-14、 15-19、 >19
All group have 3F 、 3M
2. Equipment800 MHz Pentium 3 PC with 128 MB of RAN
32 MB Riva TNT2 3D card
Virtual Research Systems V8 head mounted display
Method3.Design
Fig. 1. View seen by the participant from the starting position at the side of the road. The corner of the traffic island can be seen at bottom left.
Method4.自變項Age-4 group
Trial-uniform speed(40、 50、 60km/h)
uniform distance(65、 75、 85m)
Sex
5.依變項Collisions
Tight fits
Cautious crossings
Crossing time
Rejected gaps
Number of gaps
Method6.Procedure
Experimental session
Two training trials and 12 trials
Fig. 2. A bird’s eye view of the central portion of the road crossing environment. A vehicle is approaching the participant who is at the starting positionby the side of the road.
ResultsCollisions and tight fits
Collisions 13 time (5%) , tight fits 33 time (12%)Seven participants no collision ,one of cautious and six safe
crossing , that age10-14yeard(2M,1F) and >19 years (2M,1F)The mean number of collisions and/or tight fits per participant
for the remaining 17 participants was 2.71 (23% of trials)
ResultsCollisions and tight fits
2*4*2 ANOVA Significant on three factors
uniform distance more collisions and tight fits than uniform speed (Ms=1.25 vs 0.67 ,p=0.07 )
Female more collisions and tight fits than male (Ms=1.17 vs 0.75,p=0.30 )
Oldest participants is the lower collisions and tight fits than other younger groups (Ms=0.58 vs 1.17,0.917 and 1.17,p=0.28)
ResultsCautious crossings
On 19 trials (7%),participant cautious crossings
Data from four participant
One 5-9 group – 12 trial (63%)
One 15-19 group – 5 trial (26%)
Two other group – 2 trial (11%)
ResultsTiming measures
Participants
Crossing gapRejected gap
ResultsCrossing gaps
2*4*2 ANOVA Significant on trial, F(1,15)=5.29,p<0.05
Significant trial by sex interaction, F(1,15)=8.95,p<0.01
Post hoc tests showed crossing gap on uniform speed larger than uniform distance for female (Ms=8.56 vs7.61) ,but not for the male.
ResultsRejected gaps
Significant main effect of trial,F(1,13)=27.99,p<0.01 Mean reject gap in the uniform distance larger than uniform speed(Ms=6.55 vs 4.95)
*
ResultsComparing crossing and rejected gaps
* **
ResultsNumber of gaps
Uniform distance Uniform speed
Safe crossing 0.64 0.88
Unsafe crossing 0.01 0.74*
*
DiscussionRoad crossing behavior
年份 學者 研究結果 本研究結果19941996
Carid et al.Manser rt al.
females react differently to the VR technology than do males which may account for their greater overall incidence of unsafe crossings
1998 Morrongiello et al.
These differences have been attributed to sex-differences in cognitive-based factors such as risk appraisals and attributions
1996 Connelly Participants performed the road crossing task better in the uniform speed trials than the uniform distance trials
19841981
Lee et al.Vinje
better performance of participants in the uniform speed than uniform distance trials does not indicate that they are unable to directly perceive time-to-collision
DiscussionUsing virtual reality
The VR system used in this research
images shown to reduce the perceived
depth in an observed scene (Koenderink et al., 1994, 1995), reducing perceivers’ ability to accurately perceive the distance of the approaching vehicles.
Conclusions
the 5–9 years had the highest collisions and tight fits in the virtual environment and the <19 years the lowest incidenceThere were more collisions and tight fits in the uniform distance than in the uniform speed trialsFemales showed a slightly higher incidence of unsafe crossings than did males