Street Centerlines

<p style='margin-top:12.0pt; margin-right:0in; margin-bottom:0in; margin-left:0in; margin-bottom:.0001pt; background:white;'><b><span style='font-size:11.5pt; font-family:&quot;Helvetica&quot;,sans-serif; color:#4C4C4C;'><a href='https://maps.lakecountyil.gov/gisdata/roads.zip' target='_blank' rel='nofollow ugc noopener noreferrer'>Download In State Plane Projection Here</a>. </span></b></p>

<p style='margin-top:12.0pt; margin-right:0in; margin-bottom:0in; margin-left:0in; margin-bottom:.0001pt; background:white; font-variant-ligatures:normal; font-variant-caps:normal; text-align:start; text-decoration-style:initial; text-decoration-color:initial; word-spacing:0px;'><span style='font-size:11.5pt; font-family:&quot;Helvetica&quot;,sans-serif; color:#4C4C4C;'>**<b> The Street Centerline feature class now follows the
NG911/State of Illinois data specifications including a StreetNameAlias table.
The download hyperlink above also contains a full network topology for use with
the Esri Network Analyst extension </b>**</span></p>

<p style='margin-top:12.0pt; margin-right:0in; margin-bottom:0in; margin-left:0in; margin-bottom:.0001pt; background:white; font-variant-ligatures:normal; font-variant-caps:normal; text-align:start; text-decoration-style:initial; text-decoration-color:initial; word-spacing:0px;'><span style='font-size:11.5pt; font-family:&quot;Helvetica&quot;,sans-serif; color:#4C4C4C;'>These street centerlines were developed for a myriad of uses
including E-911, as a cartographic base, and for use in spatial analysis.</span></p>

<p style='margin-top:12.0pt; margin-right:0in; margin-bottom:12.0pt; margin-left:0in; background:white; font-variant-ligatures:normal; font-variant-caps:normal; text-align:start; text-decoration-style:initial; text-decoration-color:initial; word-spacing:0px;'><span style='font-size:11.5pt; font-family:&quot;Helvetica&quot;,sans-serif; color:#4C4C4C;'>This coverage should include all public and selected private
roads within Lake County, Illinois. Roads are initially entered using recorded
documents and then later adjusted using current aerial photography. This
dataset should satisfy National Map Accuracy Standards for a 1:1200 product.</span></p>

<p style='margin-top:12.0pt; margin-right:0in; margin-bottom:12.0pt; margin-left:0in; background:white; font-variant-ligatures:normal; font-variant-caps:normal; text-align:start; text-decoration-style:initial; text-decoration-color:initial; word-spacing:0px;'><span style='font-size:11.5pt; font-family:&quot;Helvetica&quot;,sans-serif; color:#4C4C4C;'>These centerlines have been provided to the <a href='https://www.census.gov/' target='_blank' rel='nofollow ugc noopener noreferrer'>United States
Census Bureau</a> and were used to conflate the <a href='https://www.census.gov/geographies/mapping-files.html' target='_blank' rel='nofollow ugc noopener noreferrer'>TIGER</a> road
features for Lake County. The Census Bureau evaluated these centerlines and,
based on field survey of 109 intersections, determined that there is a 95%
confidence level that the coordinate positions in the centerline dataset fall
within 1.9 meters of their true ground position.</span></p>

<p style='margin-top:12.0pt; margin-right:0in; margin-bottom:12.0pt; margin-left:0in; background:white; font-variant-ligatures:normal; font-variant-caps:normal; text-align:start; text-decoration-style:initial; text-decoration-color:initial; word-spacing:0px;'><span style='font-size:11.5pt; font-family:&quot;Helvetica&quot;,sans-serif; color:#4C4C4C;'>The fields PRE_DIR, ST_NAME, ST_TYPE and SUF_DIR are formatted
according to United States Postal Service standards.</span></p>

<p style='margin-top:12.0pt; margin-right:0in; margin-bottom:12.0pt; margin-left:0in; background:white; font-variant-ligatures:normal; font-variant-caps:normal; text-align:start; text-decoration-style:initial; text-decoration-color:initial; word-spacing:0px;'><b><span style='font-size:11.5pt; font-family:&quot;Helvetica&quot;,sans-serif; color:#4C4C4C;'>Update Frequency:</span></b><span style='font-size:11.5pt; font-family:&quot;Helvetica&quot;,sans-serif; color:#4C4C4C;'><br />
This dataset is updated on a <b>weekly</b> basis.</span></p>

**点击此处下载州平面投影（State Plane Projection）格式数据集**

**本道路中心线要素类现已遵循NG911/伊利诺伊州数据规范，包含街道名称别名表（StreetNameAlias table）。上述下载链接同时包含可配合Esri Network Analyst扩展模块使用的完整网络拓扑结构。**

本道路中心线数据集可应用于多种场景，包括增强型911（E-911）应急调度、作为制图底图以及开展空间分析工作。

本数据集覆盖伊利诺伊州莱克县内所有公共道路及部分私有道路。道路数据最初通过备案文档录入，后续结合最新航空摄影成果进行校正完善。该数据集符合1:1200比例尺产品的美国国家地图精度标准（National Map Accuracy Standards）。

本道路中心线数据集已提交至美国人口普查局（United States Census Bureau），并用于匹配莱克县的TIGER道路要素。美国人口普查局通过对109个交叉口的野外勘测对本数据集进行评估，结果显示：中心线数据的坐标位置与真实地面位置的偏差在1.9米以内的置信度为95%。

数据集中的PRE_DIR、ST_NAME、ST_TYPE及SUF_DIR字段均遵循美国邮政服务（United States Postal Service）标准格式。

**更新频率：**
本数据集每周更新一次。