Fort Worth, Texas import

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Purpose

This project will import building footprints for Forth Worth, Texas. As many buildings as possible will be addressed, tagged with basic residential/commercial tag as well as amenity/shop tags.

Permissions

Under the Texas Public Information Act, information created by government entities is considered a public record that can be requested at any time.

The City of Fort Worth has released their GIS data into the public domain with the following statement:
"The zipped shapefiles listed below are available free of charge, just click on the links to start your download. These files are supplied for illustrative purposes only. Use of information contained in or derived from these files as a substitute for the practice of registered engineers and surveyors, or in instances where examination of original documents is required is strictly prohibited. There is no warranty expressed or implied of the accuracy or completeness of material contained in the digital files supplied by the City of Fort Worth."
The building footprint data will also be joined with appraisal data to be able more efficiently categorize their use and address them. This data is provided in the public domain by the Tarrant Appraisal District.

Process

This import will follow the same process as the Dallas Import that succeeded in adding hundreds of thousands of buildings to OSM:

Data Preparation

  1. All buildings 500 square feet an under are excluded, leaving 255,866 footprints to be imported.
  2. Buildings are matched to their linked appraisal account.
  3. Street addresses from the Appraisal District's Location records were standardized into OSM addr:street and addr:housenumber tags.
  4. Standardized addresses are joined to Building footprint. For those footprints that don't have an account number, the address information in the footprint will be used.
  5. The building=* tag is assigned based on the property code in the appraisal file. Those that don't match will be given a simple building=yes value.
  6. The SIC industry code field in the building footprints will be used to tag amenities, such as grocery stores and restaurants. If the owner name field is useful, the name of the business will be included in the import.

Import into OSM

JOSM will be used to import the data into OSM. Upload changesets will use "City of Fort Worth; Texas Orthophoto" in the source field, and include the hashtags #FWTX and #DFWosm in the comments.

  • The building footprints will be verified using the Texas Orthophoto layer, which contains 2017 imagery for the city.
  • The "Replace Geometry" feature (from the utils-2 plugin) will be used to merge new geometry with existing data and preserve the feature history.
  • Buildings need to be reclassified by examining imagery and OSM data. For example, some school buildings were tagged as "building=commercial", but seeing them inside the school area allows them to be properly tagged as "building=school"

Test Area

A sample area with a variety of land uses was tested with 139 buildings and uploaded as Changeset #49012213. Sample data available here.

For the few buildings that were already traced, the imported data was superior. However, attention will be needed to ensure addressing is correct and only on main buildings, and that the building tag is appropriate.

Fort Worth Texas Import Test Results.gif