2010-2014 ACS Vehicle Availability Variables - Boundaries

This layer contains 2010-2014 American Community Survey (ACS) 5-year data, and contains estimates and margins of error. The layer shows household size by number of vehicles available. This is shown by tract, county, and state boundaries. There are also additional calculated attributes related to this topic, which can be mapped or used within analysis. This layer is symbolized to show the percentage of households with no vehicle available. To see the full list of attributes available in this service, go to the "Data" tab, and choose "Fields" at the top right. Vintage: 2010-2014 ACS Table(s): B08201 Data downloaded from: Census Bureau's API for American Community Survey Date of API call: November 11, 2020 National Figures: data.census.gov The United States Census Bureau's American Community Survey (ACS): About the Survey Geography & ACS Technical Documentation News & Updates This ready-to-use layer can be used within ArcGIS Pro, ArcGIS Online, its configurable apps, dashboards, Story Maps, custom apps, and mobile apps. Data can also be exported for offline workflows. For more information about ACS layers, visit the FAQ. Please cite the Census and ACS when using this data. Data Note from the Census: Data are based on a sample and are subject to sampling variability. The degree of uncertainty for an estimate arising from sampling variability is represented through the use of a margin of error. The value shown here is the 90 percent margin of error. The margin of error can be interpreted as providing a 90 percent probability that the interval defined by the estimate minus the margin of error and the estimate plus the margin of error (the lower and upper confidence bounds) contains the true value. In addition to sampling variability, the ACS estimates are subject to nonsampling error (for a discussion of nonsampling variability, see Accuracy of the Data). The effect of nonsampling error is not represented in these tables. Data Processing Notes: This layer has associated layers containing the most recent ACS data available by the U.S. Census Bureau. Click here to learn more about ACS data releases and click here for the associated boundaries layer. The reason this data is 5+ years different from the most recent vintage is due to the overlapping of survey years. It is recommended by the U.S. Census Bureau to compare non-overlapping datasets. Boundaries come from the U.S. Census TIGER geodatabases. Boundary vintage (2014) appropriately matches the data vintage as specified by the Census. These are Census boundaries with water and/or coastlines clipped for cartographic purposes. For census tracts, the water cutouts are derived from a subset of the 2010 AWATER (Area Water) boundaries offered by TIGER. For state and county boundaries, the water and coastlines are derived from the coastlines of the 500k TIGER Cartographic Boundary Shapefiles. The original AWATER and ALAND fields are still available as attributes within the data table (units are square meters). The States layer contains 52 records - all U.S. states, Washington D.C., and Puerto Rico Census tracts with no population that occur in areas of water, such as oceans, are removed from this data service (Census Tracts beginning with 99). Percentages and derived counts, and associated margins of error, are calculated values (that can be identified by the "_calc_" stub in the field name), and abide by the specifications defined by the American Community Survey. Field alias names were created based on the Table Shells file available from the American Community Survey Summary File Documentation page. Negative values (e.g., -4444...) have been set to null, with the exception of -5555... which has been set to zero. These negative values exist in the raw API data to indicate the following situations: The margin of error column indicates that either no sample observations or too few sample observations were available to compute a standard error and thus the margin of error. A statistical test is not appropriate. Either no sample observations or too few sample observations were available to compute an estimate, or a ratio of medians cannot be calculated because one or both of the median estimates falls in the lowest interval or upper interval of an open-ended distribution. The median falls in the lowest interval of an open-ended distribution, or in the upper interval of an open-ended distribution. A statistical test is not appropriate. The estimate is controlled. A statistical test for sampling variability is not appropriate. The data for this geographic area cannot be displayed because the number of sample cases is too small.本图层包含2010-2014年美国社区调查（American Community Survey, ACS）5年周期数据，涵盖各类估计值与误差边际。本图层按可用车辆数展示家庭规模分布，覆盖普查分区、县与州界范围。此外还包含与该主题相关的额外计算属性，可用于制图或分析工作。 本图层已完成符号化配置，用于展示无可用车辆的家庭占比。如需查看本服务中可用属性的完整列表，请前往「数据」选项卡，并选择右上角的「字段」选项。 数据年份：2010-2014年ACS；数据表编号：B08201；数据来源：美国人口普查局美国社区调查API；API调用日期：2020年11月11日；全国统计数据来源：data.census.gov。 关于美国社区调查（ACS）：可参考调查说明、地理与ACS技术文档、新闻与更新板块。 本图层为即用型数据，可在ArcGIS Pro、ArcGIS Online、其可配置应用、仪表板、故事地图、自定义应用及移动应用中使用，也可导出数据用于离线工作流程。如需了解ACS图层的更多信息，请访问常见问题解答（FAQ）页面。使用本数据时，请引用美国人口普查局与ACS。 美国人口普查局的数据说明：本数据基于抽样调查，存在抽样变异性。由抽样变异性导致的估计值不确定程度通过误差边际体现。本处展示的为90%置信水平的误差边际，其含义为：估计值加减误差边际所形成的区间（即置信上下限）有90%的概率包含真实数值。除抽样变异性外，ACS估计值还存在非抽样误差（关于非抽样变异性的讨论，请参阅《数据精度》文档），本数据表未体现非抽样误差的影响。 数据处理说明：本图层附带美国人口普查局发布的最新ACS数据关联图层。点击此处可了解ACS数据发布详情，点击此处可获取关联的边界图层。本数据集与最新可用数据年份相差5年以上，是由于调查年份存在重叠所致。美国人口普查局建议使用非重叠数据集进行对比分析。 本图层的边界数据来自美国人口普查局TIGER地理数据库。边界年份（2014年）与普查局指定的数据年份匹配。为满足制图需求，已对包含水域及海岸线的普查边界进行裁剪：对于普查分区，水域裁剪范围源自TIGER提供的2010年AWATER（水域面积）边界子集；对于州与县界，水域及海岸线源自50万比例尺TIGER制图边界形状文件的海岸线数据。原始AWATER与ALAND字段仍作为数据表格中的属性保留（单位：平方米）。 州图层包含52条记录，涵盖美国所有州、华盛顿哥伦比亚特区及波多黎各。本数据服务已移除位于水域（如海洋）区域的无人口普查分区（编号以99开头的普查分区）。 占比、衍生计数及相关误差边际均为计算所得值（可通过字段名中的「_calc_」前缀识别），并严格遵循美国社区调查的规范。字段别名基于美国社区调查汇总文件文档页面提供的表壳文件生成。 除-5555...已被设置为0外，其余负值（如-4444...）均已被设置为空值。原始API数据中的这些负值用于标识以下情况： 1. 误差边际列表明无有效抽样观测值或抽样观测值过少，无法计算标准误及误差边际，不适合进行统计检验； 2. 无有效抽样观测值或抽样观测值过少，无法计算估计值；或由于其中一个或两个中位数估计值落在开放式分布的最低区间或最高区间，无法计算中位数比率； 3. 中位数落在开放式分布的最低区间或最高区间，不适合进行统计检验； 4. 估计值已受控，不适合进行抽样变异性统计检验； 5. 由于抽样案例数量过少，无法展示本地理区域的数据。