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 Height et al. Connelly et al. Pedestrian death and serious injury to young children is the most common causes Jonah et al. Land et al. The highest Pedestrian deaths is years have 17% ， fellow this have 14% 5-9 and10-14 have 3% 1991ThomsonThis have been identified Young children road crossing Demetre et al. Pitcairn et al. Young children to be worse at making safe road crossing decisions than older child and adults

Method 1.Participants Total 24 people, range 5~30 years Age group 5-9 、 、 、 >19 All group have 3F 、 3M 2. Equipment 800 MHz Pentium 3 PC with 128 MB of RAN 32 MB Riva TNT2 3D card Virtual Research Systems V8 head mounted display

Method 3.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.

Method 4. 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

Method 6.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 position by the side of the road.

Results Collisions 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)

Results Collisions 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)

Results Cautious crossings On 19 trials (7%),participant cautious crossings Data from four participant One 5-9 group – 12 trial (63%) One group – 5 trial (26%) Two other group – 2 trial (11%)

Results Timing measures Participants Crossing gapRejected gap

Results Crossing 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.

Results Rejected 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) *

Results Comparing crossing and rejected gaps * * *

Results Number of gaps Uniform distance Uniform speed Safe crossing Unsafe crossing * *

Discussion Road crossing behavior 年份學者研究結果本研究結果 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 1998Morrongiello et al. These differences have been attributed to sex- differences in cognitive-based factors such as risk appraisals and attributions 1996ConnellyParticipants performed the road crossing task better in the uniform speed trials than the uniform distance trials 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

Discussion Using 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 incidence There were more collisions and tight fits in the uniform distance than in the uniform speed trials Females showed a slightly higher incidence of unsafe crossings than did males