What do cyclists need to see to avoid single-bicycle crashes?

The number of single-bicycle crash victims is substantial in countries with high levels of cycling. To study the role of visual characteristics of the infrastructure, such as pavement markings, in single-bicycle crashes, a study in two steps was conducted. In Study 1, a questionnaire study was conducted among bicycle crash victims (n = 734). Logistic regression was used to study the relationship between the crashes and age, light condition, alcohol use, gaze direction and familiarity with the crash scene. In Study 2, the image degrading and edge detection method (IDED-method) was used to investigate the visual characteristics of 21 of the crash scenes. The results of the studies indicate that crashes, in which the cyclist collided with a bollard or road narrowing or rode off the road, were related to the visual characteristics of bicycle facilities. Edge markings, especially in curves of bicycle tracks, and improved conspicuity of bollards are recommended. Statement of Relevance: Elevated single-bicycle crash numbers are common in countries with high levels of cycling. No research has been conducted on what cyclists need to see to avoid this type of crash. The IDED-method to investigate crash scenes is new and proves to be a powerful tool to quantify 'visual accessibility'. © 2011 Taylor & Francis

Exploring older adults hearing and vision and driving – the Swedish study

Aim: The aims of this study were to evaluate the self-reported driving abilities and use of visual and hearing aids for driving, among older adults with varying degrees of hearing impairment (HI), vision impairment (VI) and dual sensory impairment (DSI). Visual processing related to driving performance was also assessed to provide a laboratory-based index of driving ability and safety. The research examined the associations between self-reported and clinically measured vision and hearing, and how they related to the level of comfort in various driving situations and the use of hearing and vision aids (spectacles) when driving. Method: Participants included 109 older adults (58 women, 51 men) aged over 60 years (M age = 69.5 years (SD = 5.25), age range: 60–87) who held a valid driver's license. Following attendance at the testing session that involved clinical measures of vision and hearing and an assessment of visual processing abilities, the participants were categorized into four groups according to their hearing and vision abilities: no visual or hearing impairment (NI), corrected visual impairment (CVI), hearing impairment (HI), and corrected visual impairment combined with hearing impairment (CVHI). All participants filled in a questionnaire covering subjective measures of vision, hearing, driving habits, and use of vision and hearing aids. Results and Conclusion: There was a strong association between most of the subjective and objective measures of both hearing and vision, which indicates that participants in this study were aware of their abilities to some extent. Better hearing and vision measures were associated with higher level of comfort in several traffic situations. The results also show that spectacles are used more than hearing aids when driving (95% versus 57% of the time respectively). In addition, both the measured and the experienced benefits of hearing aids were significantly associated with the amount of hearing aid use when driving. The findings of this study provide the basis for larger scale studies to explore the impact of hearing and visual impairment on driving and the use of vision and hearing aids and should also include participants who have visual impairment even with their optimal optical correction to fully explore these effects