The effect of light rail transit on physical activity: a natural experiment

项目总结/摘要 轻轨交通对体力活动的影响：一项自然实验 大多数美国成年人无法获得足够的身体活动，尽管有许多健康益处 与更活跃有关。对环境因素的兴趣和证据日益增加， 影响身体活动，如邻里设计和交通基础设施，已受到阻碍， 限制因果推理能力的横截面设计。本研究利用了一个 即将到来的交通环境的显着变化，在南部引入轻轨交通（LRT） King County（西雅图地区）和LRT车站周围社区建筑环境的可能变化， 更好地了解建筑环境对交通相关步行和整体身体的因果影响 活动采用病例对照纵向面板控制设计，1000名成年人居住在接近（1 英里半径;情况）或远离（控制）LRT车站，这些人在人口统计学上和初始 邻里建成环境，将评估之前（基线），不久后（后1），和超过2 （二）开通轻轨服务后。据推测，居住在轻铁附近的居民 与交通有关的步行增加（例如，往返轻铁车站（从家、工作地点）和总计 在短期和长期内，与居住在较远地方的居民相比，短期 增长可能仅限于轻轨用户，但据推测，交通的长期增长 步行和总的体力活动将由轻轨的使用和轻轨周围建筑环境的变化引起 促进步行的车站。这些变化将包括增加住宅密度、土地用途组合， 零售通道和行人基础设施。个人的运输步行将通过7天的旅行进行评估 日记和通过加速度计评估的身体活动。街区建成环境及其变化 将通过地块级土地利用评估进行评估。此外，现有非轻铁交通工具的改变 基础设施（例如，巴士路线）及是否有巴士供应，对变化的前瞻性评价 在同一个人的交通方式和身体活动在一段时间内预期的显着变化， 交通资源和建筑环境是一个罕见的，但有力的考验环境的影响可以有 健康行为。这样的评估是必要的，以推动积极的生活研究领域和更多 重要的是，更好地向决策者通报交通系统变化的后果， 建筑环境。项目叙述 轻轨交通对体力活动的影响：一项自然实验 拟议的项目对公共卫生政策和研究具有重要意义，对健康的影响包括： 美国日益增长的公共交通系统以及对建筑环境领域的更广泛影响 和体力活动。这种能力可以更好地从建筑环境对环境的影响中得出因果推断， 交通相关的和总的身体活动是至关重要的，以告知是否建成环境改造， 唤起这种必要的健康行为改变，因此对告知公共卫生政策至关重要。

Project Summary/Abstract The effect of light rail transit on physical activity: a natural experiment The majority of U.S. adults fail to obtain adequate physical activity, despite the numerous health benefits associated with being more active. Growing interest in and evidence regarding the environmental factors that affect physical activity, such as neighborhood design and transportation infrastructure, has been hampered by cross-sectional designs that limit the ability to draw causal inference. The present study takes advantage of an upcoming marked change in the transportation environment, the introduction of light rail transit (LRT) in south King County (Seattle area) and likely changes in the neighborhood built environment around LRT stations, to better understand the causal effects of built environment on transportation-related walking and overall physical activity. Using a case-control longitudinal panel controlled design, 1000 adults living either close to (within 1 mile radius; case) or far from (control) an LRT station who are similar demographically and in initial neighborhood built environment, will be assessed prior to (baseline), soon after (post 1), and more than 2 years after (post 2) the introduction of LRT service. It is hypothesized that residents living close to LRT will have an increase in transportation-related walking (e.g., to/from LRT stations from home, work) and total physical activity relative to residents living farther away in both the short- and long-term. The short-term increases will likely be confined to LRT users, but it is hypothesized that long-term increases in transport walking and total physical activity will result from LRT use and changes in the built environment around LRT stations that promote walking. Such changes would include increases in residential density, land use mix and retail access, and pedestrian infrastructure. Individuals' transport walking will be assessed via 7-day travel diaries and physical activity assessed via accelerometry. Neighborhood built environment and changes therein will be assessed via parcel-level land use evaluation. In addition, changes in existing non-LRT transportation infrastructure (e.g., bus routes) and availability will also be considered. The prospective evaluation of changes in the same individuals' transport modes and physical activity over a period of expected marked change in transportation resources and built environment is a rare, but potent test of the impact environment can have on health behaviors. Such evaluations are needed to move forward the field of active living research and more importantly to better inform policy makers regarding consequences of changes in transportation systems and the built environment. Project Narrative The effect of light rail transit on physical activity: a natural experiment The proposed project has significance for public health policy and research, with health impact implications for the growing public transportation system in the U.S. and broader implications for the field of built environment and physical activity. This ability to better draw causal inference from the impact of built environment on transportation-related and total physical activity is critical to informing whether built environment modification can evoke such needed health behavior changes and is therefore essential to informing public health policy.