Contributory Factors to critically wrong road-crossing judgements among older people: an integrated research study

Introduction Older people are having higher risk of vehicle-pedestrian collisions. This study examines the relative importance of different environmental, physical and cognitive factors in contributing to critically wrong road-crossing judgements. Methods An integrated research design is adopted. Older pedestrians were recruited through Elderly Community Centres in Hong Kong. Data about their physical and cognitive ability were collected through setting up outreach laboratories within the participants' neighbourhood communities. In addition to obtaining two walking speeds, three clinical tests (the visual acuity test, Timed Up and Go test and Mini Mental State Examination [MMSE] test) were conducted. A questionnaire survey collected personal information and activity data. Eighteen different road-crossing scenarios showing the same dual-lane one-way local road with different traffic conditions (a vehicle approaching at different distances, at different speeds, and on different lanes) were captured in videos and presented to the participants. Their decision time and judgement for each scenario were recorded in a computer. Apart from descriptive statistics, a binary logistic generalised estimating equation model was estimated. The dependent variable is whether a road-crossing judgement was critically wrong or not. Results and Conclusions A total of 7,182 road-crossing judgements of 399 older people were collected. The most statistically significant factors contributing to critically wrong road-crossing judgements are the road environment variables of the speed and distance of the oncoming vehicle. On physical variables, walking speed is the most important factor. Lastly, the cognitive variable of MMSE score is significant. For the mild and moderate impairment groups, the chances of making a critically wrong judgement are 1.83 and 2.01 times that of the normal group respectively.