Street-Crossing Decision Making in Low Vision

描述（由申请人提供）：过马路是一项复杂，困难和危险的任务。 在决定过街时，行人必须考虑到一个优选的安全裕度，并判断车辆交通的差距是否超过过街所需的时间。 先前的过街研究表明，老年人、视力受损者和盲人行人会做出不安全的过街决定。 本研究将评估这些高风险行人群体的过街决策绩效。 我们将使用一种创新的无标准度量标准来评估行人判断的准确性和可靠性 是否有足够时间让他们横过马路。 的 行人所选择的安全幅度将不包括在决定过路处的范围内。 我们还将通过确定每个行人第一次认为可以安全过马路时的差距时间来衡量每个行人的过马路标准。 行人的安全裕度将包括在这个交叉决定中。 收集的数据将用于四个目标。 目标1将评估过街决策能力如何随着视力（视敏度、对比敏感度和视野）以及行人特征（年龄和步行速度）而变化。 如果行人在决定过马路时不补偿他们的感官和运动限制，我们预计他们的准确性和/或可靠性会相应下降，过马路的标准也会缩短。 如果行人弥补他们的局限性，并采取保守或谨慎的过街策略，则会发现匡威。目标2将比较自我报告过街有困难的视障和盲人行人与自我报告没有困难的视障和盲人行人之间的准确性，可靠性和过街标准。 如果过街决策的表现与行人的自信心有关，那些自我报告有困难的行人会表现出不安全的过街决策。 没有困难的行人会表现出安全的过街决定。 目标3将测试假设行人的准确性，可靠性和标准的交叉提高训练后，与当前的方向和移动性（O&M）过街决策培训计划。 目标4将比较在三种不同类型的交叉口环境中测量的行人过街的准确性、可靠性和标准。 在不同环境中一致的过街决策行为表明，这项研究的结果是普遍的。 不一致的决策行为将是有益的，值得进一步调查。 总的来说，该项目的研究结果将提供一个更详细的了解的因素，影响过街决策的表现。 他们还将指导为低视力（LV）康复专家制定客观的循证建议，以确定他们何时应该将患者转诊到过街决策培训。 公共卫生相关性：随着人群中低视力发病率的增加，人们越来越努力地通过在过街决策中进行专门的定向和移动性（O&M）培训来改善行人安全。 本研究将使用各种量化的方法，评估视障、盲人及老年人在真实的户外交通环境中的过街决策表现。 从这些测量，我们将确定是否过街决策培训可以提高视力障碍和盲人的安全，以及是否受试者的特点，视觉功能，感知自己的能力，以及过街环境的特点影响他们的能力，使过街决策。

DESCRIPTION (provided by applicant): Crossing the street is a complex, difficult and dangerous task. When making street-crossing decisions, pedestrians must allow for a preferred safety margin and judge whether the gap in vehicular traffic exceeds the time needed to cross the street. Previous street-crossing research has shown that the elderly, visually impaired, and blind pedestrians make unsafe street-crossing decisions. This study will evaluate the street-crossing decision making performance of these high-risk pedestrian groups. We will use an innovative criterion-free metric to evaluate the accuracy and reliability of pedestrians' judgments on whether the vehicular gap time is of sufficient duration to allow them to cross the street. The pedestrian's preferred safety margin will not be included in this crossing decision. We will also measure each pedestrian's criterion for crossing by determining the gap time when each pedestrian first thinks that it is safe to cross. The pedestrian's safety margin in this crossing decision will be included. The collected data will address four aims. Aim 1 will assess how street-crossing decision making performance changes as a function of vision (visual acuity, contrast sensitivity and visual fields), and a pedestrian's characteristics (age and walking speed). If pedestrians do not compensate for their sensory and motor limitations when making their street-crossing decisions, we expect to see a corresponding decrease in their accuracy and/or reliability and a shortened criterion for crossing. If pedestrians compensate for their limitations and adopt a conservative or cautious street-crossing strategy the converse will be found. Aim 2 will compare the accuracy, reliability and criterion for crossing between visually impaired and blind pedestrians who self-report having difficulty crossing the street and those who self-report having no difficulty. If street-crossing decision making performance is related to a pedestrian's self-confidence, those pedestrians who self-report having difficulty would exhibit unsafe street-crossing decisions. Pedestrians who have no difficulty would exhibit safe street-crossing decisions. Aim 3 will test the hypothesis whether pedestrian accuracy, reliability and the criterion for crossing improves after training with a current Orientation and Mobility (O&M) street-crossing decision training program. Aim 4 will compare the accuracy, reliability and criterion for crossing in pedestrians measured at three different types of crossing environments. Consistent street-crossing decision making behavior across different environments would suggest that the study's findings are generalizable. Inconsistent decision behavior would be informative and warrant further investigation. Collectively, the project's findings will provide a more detailed understanding of the factors that affect street-crossing decision making performance. They will also guide the development of objective evidence-based recommendations for low vision (LV) rehabilitation specialists about when they should refer patients for street-crossing decision training. PUBLIC HEALTH RELEVANCE: The increasing incidence in low vision in the population is resulting in increased efforts to improve pedestrian safety through specialized orientation and mobility (O&M) training in street-crossing decision making. Using various quantitative measures, we will evaluate the street-crossing decision making performance of visually impaired, blind and elderly pedestrians in real, outdoor traffic environments. From these measurements, we shall determine whether street-crossing decision training can improve the safety of visually impaired and blind people and whether a subject's characteristics, vision functions, perception of their own ability, and the characteristics of the crossing environment affect their ability to make street-crossing decisions.