ACS Transportation to Work Variables - Boundaries

Retirement Notice: This item is in mature support as of February 2026 and will retire in December 2027. A new version of this item is available for your use. Esri recommends updating your maps and apps to use the new version. This layer shows workers' place of residence by mode of commute. This is shown by tract, county, and state boundaries. This service is updated annually to contain the most currently released American Community Survey (ACS) 5-year data, and contains estimates and margins of error. There are also additional calculated attributes related to this topic, which can be mapped or used within analysis. This layer is symbolized by the percentage of workers who drove alone. To see the full list of attributes available in this service, go to the "Data" tab, and choose "Fields" at the top left. Vintage: 2019-2023 ACS Table(s): B08301 (Not all lines of this ACS table are available in this feature layer.) Data downloaded from: Census Bureau's API for American Community Survey Date of API call: December 12, 2024 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 and 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 is updated automatically when the most current vintage of ACS data is released each year, usually in December. The layer always contains the latest available ACS 5-year estimates. It is updated annually within days of the Census Bureau's release schedule. Click here to learn more about ACS data releases. Boundaries come from the US Census TIGER geodatabases, specifically, the National Sub-State Geography Database (named tlgdb_(year)_a_us_substategeo.gdb). Boundaries are updated at the same time as the data updates (annually), and the boundary vintage appropriately matches the data vintage as specified by the Census. These are Census boundaries with water and/or coastlines erased for cartographic and mapping purposes. For census tracts, the water cutouts are derived from a subset of the 2020 Areal Hydrography boundaries offered by TIGER. Water bodies and rivers which are 50 million square meters or larger (mid to large sized water bodies) are erased from the tract level boundaries, as well as additional important features. For state and county boundaries, the water and coastlines are derived from the coastlines of the 2023 500k TIGER Cartographic Boundary Shapefiles. These are erased to more accurately portray the coastlines and Great Lakes. 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 US 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.

停用通知：本数据集自2026年2月起进入成熟支持阶段，并将于2027年12月正式停用。当前已有新版本可供使用，Esri建议您更新地图与应用以适配新版本。
本图层展示了按通勤方式划分的就业人员居住地分布，以普查区（tract）、县（county）及州（state）界为统计单元。本服务每年更新一次，纳入最新发布的美国社区调查（American Community Survey, ACS）5年调查数据，包含估计值与误差边际。此外还提供了与该主题相关的额外计算属性，可用于制图或分析。
本图层以独自驾车通勤的就业人员占比进行符号化展示。如需查看本服务中所有可用属性的完整列表，请前往"数据"选项卡，并选择左上角的"字段"菜单。
数据时段：2019-2023年ACS 数据表：B08301（本要素图层未包含该ACS数据表的全部行）。
数据下载自：美国人口普查局（Census Bureau）美国社区调查API
API调用日期：2024年12月12日
全国统计数据：data.census.gov
美国人口普查局美国社区调查（ACS）： 关于本调查 地理与ACS技术文档 新闻与更新
本即用型图层可在ArcGIS Pro、ArcGIS Online及其可配置应用、仪表盘、Story Maps、自定义应用与移动应用中使用。数据也可导出用于离线工作流程。如需了解更多ACS图层相关信息，请访问常见问题解答（FAQ）。使用本数据时请注明引用美国人口普查局与ACS。
美国人口普查局数据说明：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（margin of error）体现。此处展示的为90%置信水平的误差边际，其含义为：估计值减去误差边际与估计值加上误差边际所构成的区间（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，请参见《数据准确性》一文），本表格未体现非抽样误差的影响。
数据处理说明：本图层将在每年最新时段的ACS数据发布时自动更新，通常于每年12月完成。本图层始终包含最新可用的ACS 5年调查估计值，将在美国人口普查局发布数据后的数日内完成年度更新。点击此处了解更多ACS数据发布相关信息。
地理边界源自美国人口普查局TIGER地理数据库，具体为全国次州级地理数据库（命名格式为tlgdb_(年份)_a_us_substategeo.gdb）。边界将与数据同步每年更新，且边界时段与美国人口普查局指定的数据时段完全匹配。为制图与可视化需求，本数据集已移除普查边界中的水体及海岸线要素。对于普查区，水体裁剪源自TIGER提供的2020年区域水文边界子集：面积大于等于5000万平方米的大中型水体及其他重要地物已从普查区边界中移除。对于州与县级边界，水体及海岸线源自2023年50万比例尺TIGER制图边界形状文件的海岸线数据，经移除后可更精准地展示海岸线与五大湖区域。数据表格中仍保留原始的AWATER与ALAND字段（单位：平方米）。
州图层共包含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。
本数据服务中已移除位于水域（如海洋）区域且无人口的普查区（普查区代码以99开头）。
百分比、衍生计数及对应的误差边际均为计算所得值（字段名称中带有"_calc_"前缀），并严格遵循美国社区调查的相关规范。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（Table Shells file）生成。
除-5555…已被设置为0外，其余负值（例如-4444…）均已被设置为空值。原始API数据中的这些负值用于指示以下情况：
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，此时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分布的最低区间或最高区间，无法计算中位数比值。
3. 中位数落在开放分布的最低区间或最高区间。
4. 不适合进行统计检验。
5. 估计值已受控，不适合进行抽样变异性统计检验。
6. 本地理区域的样本量过小，无法展示数据。