The Pedestrian Road-Crossing Behaviors between Older and Younger Age Groups Ying-Chan Tung, Yung-Ching Liu, and Yang-Kun Ou† Department of Industrial Engineering and Management National Yunlin University of Science and Technology 123 Sec. 3, University Rd., Douliu, Yunlin 640, Taiwan Corresponding author’s e-mail:
[email protected]
Abstract. The purpose of this study is to investigate the age effect of pedestrian road-crossing behaviors. Four factors were involved in this mixed factorial experiment study, including the age (younger: 20 ~ 30 years old; older: above 65 years old; between -subjects), vehicle speed (40 km/hr, 60 km/hr, 80 km/hr; withinsubjects) , time gap (3 seconds, 5 seconds, 7 seconds; within-subjects) and time of day (midday: 11:00 ~ 13:00; dusk: 17:50 ~ 18:10; within-subjects). Three 32 inches of liquid crystal displays (LCD) were employed to present pre-recorded road environment videos. Thirty-two voluntary participants were required to stand in front of the LCDs and complete 72 road-crossing decision trials arranged in random sequence. The safety crossing time, subjective confidence and crossing pace were collected as the dependent variables. The results showed that the elders walk paces were slower than those of the young people and thus caused the elders to take higher risk when crossing the road. The dusk time was more risky than the midday time for both age groups because of poor visual acuity and thus both groups misjudged the distance between vehicles and themselves. Both age groups took the distance to the approaching vehicle into account firstly when they decided to cross the road and then considered the speed of an oncoming vehicle. The faster the speed, the more risky of collision for the pedestrian; the longer the time gap, the longer remaining time the pedestrian chose. The application of this study can provide design and education insights for improving road traffic safety. Keywords: Age, Pedestrian, Road-Crossing, Safety Margin
1. INTRODUCTION According to the Traffic Accident Analysis of the Minister of the Interior, fatal traffic accidents occur more in cars and pedestrians in Taiwan. The old age group (above 65) has shown a highest mortality rate. The cause of fatal traffic accidents due to pedestrians’ or passengers’ fault was 2.95% (Traffic accident A1 2001~2007 April statistical data). Over the years, accidents occur more frequently between 18:00 to 20:00 (12.15%), then between 20:00 to 22:00 (9.67%). The results showed that there is a tendency for traffic accidents to occur with especial frequency in the period of dusk. Taiwan is becoming an aged society. The purpose of the research is using the crossing-road experiment to investigate different age groups of pedestrians’ (the older and younger) judgment and response capabilities when they cross roads. It also aims to discuss road-crossing behavior in the old, finally to provide insight
into improving road safety. The elders’ physical movement becomes slower especially as they reached at the age of 65 (Guerrier et al., 1998; Tarawneh, 2001; Oxley et al., 1997).An experiment conducted by Oxley et al. (2005) was to compare the walking time of different age groups walking 5.6 meters with faster walking pace and normal walking pace. Result showed that for different age groups, the normal and fast walking times were significantly different. In general, age over 65 commonly walked slowest than the other age groups. Many investigations have indicated that the main factor for pedestrians making their road crossing decision is based on the distance between the oncoming vehicle and themselves (Oxley et al., 2006; Oxley et al., 2005). Similar result was found in Connelly et al. (1998) study that 63% people use the distance factor as their road crossing main decision factor and only 10% people use the approaching
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APIEMS 2008 Proceedings of The 9th Asia Pasific Industrial Engineering & Management Systems Conference vehicle speed. Under different vehicle speed, the pedestrian reduced the time gap with vehicle speed increase when they have crossing time constraint (Connelly et al, 1996; Lobjois et al., 2007). The safety margin concept was used to judge pedestrians road crossing safely in many research. Guth et al. (2005) and Oxley et al. (1997) studies showed that drunk people make the lowest safety margin. Oxley et al. (2006) and Oxley et al.(2005) indicated that the elderly crossing-road pedestrian produce the lower safety margin. The lower safety margin represents unsafe crossing-road behavior. The pedestrian cross road will be affected by external factors such as number of coming vehicle, the other nearby pedestrian behavior (Yagil, 2000; Yang et al., 2006). An observation study was conducted by Keegan et al. (2003) and found the traffic signal providing with the additional time countdown information will cause pedestrian to wait for the signal change from red to green before crossing the road and thus increase safety. Tarawneh (2001) found that increasing the road width will make pedestrian cross road fast. 2. Method 2.1 Participants Sixteen National Yunlin University of Science and Technology students were recruited as the younger pedestrian group participating in this experiment (9 male and 7 female). The age range was 24-29 years (mean=26.06, S.D.=1.34). The other sixteen elder participants from Yunlin County formed the older pedestrian group (6 male and 10 female, age range from 61-79). The visual acuity for the younger group was at least 0.8, and for the older group was 0.32. All participants were required to pass color vision, normal aural comprehension, and no other musculoskeletal injury.
experiment study, including the age (younger vs. older; between -subjects), vehicle speed (40km/hr vs. 60 km/hr vs. 80 km/hr; within-subjects), time gap (3 seconds vs. 5 seconds vs. 7 seconds; within-subjects) and time of day (midday: 11:00 ~ 13:00 vs. dusk: 17:50 ~ 18:10; withinsubjects). Dependent variables including: (1) 10 meters walk speed: normal walking pace and fast walking pace. (2) time remaining (the time period remains for pedestrian safely crossing-road) which can be obtained by (time gap – the time of participant can safely crossing-road with his walking pace). (3) Degree of confidence: participants were asked to give subjective ratings between 0 and 100 for expressing their confidence in crossing the road safely (0 = low confidence, 100 = high confidence). 2.4 Procedure Participants were first given information about the purpose of this experiment and the task they were instructed to perform. The participants consent this study and then started to practice 4-10 training trials to get familiar with this experiment. The participant then walked 10 meters with two different speed pace i.e. normal walk pace and fast walking pace, and their walking time were collected. In the real trial, each participant stood in front of the 32 inches LCD located at the height of eye position. They were instructed to place their index finger on the “space” key at the keyboard. The participant subjectively assessed the time of walking 3.5 meters. The task was then based on their time estimation to make the judgment by pressing the space button at the point in which they had decided it was safe to cross the road. At this moment, the participant should say “pass” loudly. The experimenter then collected the time from the start to the verbal response. A total 72 experimental trials was randomly assigned to the participant and it was 4 trials for each road crossing condition. The experiment took approximately 1 hour.
2.2 Apparatus The experiment was conducted using a HP notebook with an Intel Pentium-M 1.73MHz processor. Three 32inch LCDs (PHILIPS 32PF1700T/96) were used to present pre-recorded road environment videos and each with the left, the central, or the right side road scenery from the pedestrian’s view point. The pre-recorded roadway scene consisted of a straight 2 lanes with relatively few intersections and little traffic and was edited by the software U-lead Video Studio and Flash. 2.3 Experimental design Four factors were involved in this mixed factorial
3. Results 3.1 Walk speed Results indicated that the younger pedestrians walked faster than those of the older ones [F(1,30)=33.061, P
