an investigation of road crossing in a virtual environment student ：董瑩蟬

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