Texas Basemap - Transportation Map Data

This resource contains statewide networks of roadways, railroads, bridges, and low-water crossings, for Texas only.

Roadways detail: The Transportation Planning and Programming (TPP) Division of the Texas Department of Transportation (TxDOT) maintains a spatial dataset of roadway polylines for planning and asset inventory purposes, as well as for visualization and general mapping. M values are stored in the lines as DFOs (Distance From Origin), and provide the framework for managing roadway assets using linear referencing. This dataset covers the state of Texas and includes on-systems routes (those that TxDOT maintains), such as interstate highways, U.S. highways, state highways, and farm and ranch roads, as well as off-system routes, such as county roads and local streets. Date valid as of: 12/31/2014. Publish Date: 05/01/2015. Update Frequency: Quarterly.

Bridges detail: As with the roadways, both on-system and off-system bridges are maintained in separate datasets (54,844 total bridges, 36,007 on-system and 18,837 off-system). Bridges have numerous useful attributes, see coding guide [1] for documentation. One such attribute identifies structures that cross water: the second digit of Item 42 “Type of Service”. If the second digit is between 5 and 9 (inclusive) then the structure is over water. The bridges datasets are valid as of December 2016.

The roadways and bridges datasets contained here were obtained directly from TxDOT through personal correspondence. An additional transportation data resource is the Texas Natural Resources Information System (TNRIS) [3]. The railroads and low-water crossings were obtained through TNRIS.

November 2023 updates: in the years since this data archive was first published, TxDOT has developed an open data portal for downloading their roadway inventory and other datasets. Also, in 2023 TNRIS was renamed as the Texas Geographic Information Office (TxGIO). Their datahub [3] is continually evolving, but still has the tnris.org domain for now. We are not updating any of the basemap data in the contents list below, which was current at the time of Hurricane Harvey.

References
[1] TxDOT Bridges Coding Guide (download below)
[2] TxDOT Open Data Portal [https://gis-txdot.opendata.arcgis.com/]
[3] TNRIS/TxGIO data downloads [https://data.tnris.org/]

本资源收录了德克萨斯州全州范围内的道路、铁路、桥梁以及浅滩的州级网络信息。道路详情：德克萨斯州交通运输部（TxDOT）的运输规划与编程（TPP）部门维护了一个用于规划、资产清单、可视化以及一般地图绘制的道路多边形空间数据集。M值以起点距离（DFOs）的形式存储在线路上，为利用线性引用管理道路资产提供了框架。该数据集涵盖了德克萨斯州全境，包括由TxDOT维护的系统内路线（如州际公路、美国公路、州公路以及农场和牧场道路），以及系统外路线（如县道路和地方街道）。数据有效日期为：2014年12月31日。发布日期：2015年5月1日。更新频率：每季度一次。

桥梁详情：与道路类似，系统内和系统外桥梁分别维护在独立的数据集中（总计54,844座桥梁，其中系统内36,007座，系统外18,837座）。桥梁数据集包含众多有用属性，具体见编码指南[1]以获取文档。其中一项属性用于标识跨越水域的结构：项目42“服务类型”的第二位数字。如果第二位数字在5到9之间（含），则该结构位于水域之上。桥梁数据集有效日期为2016年12月。

此处包含的道路和桥梁数据集直接从TxDOT通过个人通信获得。此外，德克萨斯州自然资源信息系统（TNRIS）[3]也是一项交通数据资源。铁路和浅滩信息通过TNRIS获得。

2023年11月更新：自本数据档案首次发布以来，TxDOT已开发了一个开放数据门户，用于下载其道路清单和其他数据集。此外，2023年TNRIS更名为德克萨斯州地理信息办公室（TxGIO）。其数据中心[3]持续发展，但暂时仍保留tnris.org域名。以下列表中不更新任何基础地图数据，这些数据在哈维飓风发生时是有效的。

参考文献
[1] TxDOT桥梁编码指南（下载见下文）
[2] TxDOT开放数据门户 [https://gis-txdot.opendata.arcgis.com/]
[3] TNRIS/TxGIO数据下载 [https://data.tnris.org/]