Tagscreenshot

How to extract highways and subway lines from OpenStreetMap as a shapefile

It’s possible to use Overpass Turbo to extract any object from the OpenStreetMap “planet” and convert it from a GeoJSON or KML file to a shapefile for manipulation and analysis in GIS.

Say you want the subway lines for Mexico City, and you can’t find a GTFS file that you could convert to shapefile, and you can’t find the right files on Sistema de Transporte Colectivo’s website (I didn’t look for it).

Here’s how to extract the subway lines that are shown in OpenStreetMap and save them as a GIS shapefile.

This is my second tutorial to describe using Overpass Turbo. The first extracted places of worship in Cook County. I’ve also used Overpass Turbo to extract a map of campgrounds

Extract free and open source data from OpenStreetMap

  1. Open the Overpass Turbo website and, on the map, search for the city from which you want to extract data. (The Overpass query will be generated in such a way that it’ll only search for data in the current map view.)
  2. Click the “Wizard” button in the top toolbar. (Alternatively you can copy the code below and paste it into the text area on the website and click the “Run” button.)
  3. In the Wizard dialog box, type in “railway=subway” in order to find metro, subway, or rapid transit lines. (If you want to download interstate highways, or what they call motorways in the UK, use “highway=motorway“.) Then click the “build and run query” button.
  4. In a few seconds you’ll see lines and dots (representing the metro or subway stations) on the map, and a new query in the text area. Notice that the query has looked for three kinds of objects: node (points/stations), way (the subway tracks), relation (the subway routes).
  5. If you don’t want a particular kind of object, then delete its line from the query and click the “Run” button. (You probably don’t want relation if you’re just needing GIS data for mapping purposes, and because routes are not always well-defined by OpenStreetMap contributors.)
  6. Download the data by clicking the “Export” button. Choose from one of the first three options (GeoJSON, GPX, KML). If you’re going to use a desktop GIS software, or place this data in a web map (like Leaflet), then choose GeoJSON. Now, depending on what browser you’re using, a couple things could happen after you click on GeoJSON. If you’re using Chrome then clicking it will download a file. If you’re using Safari then clicking it will open a new tab and put the GeoJSON text in there. Copy and paste this text into TextEdit and save the file as “mexico_city_subway.geojson”.
Overpass Turbo screenshot 1 of 2

Screenshot 1: After searching for the city for which you want to extract data (Mexico City in this case), click the “Wizard” button and type “railway=subway” and click run.

Overpass Turbo screenshot 2

Screenshot 2: After building and running the query from the Wizard you’ll see subway lines and stations.

Overpass Turbo screenshot 3

Screenshot 3: Click the Export button and click GeoJSON. In Chrome, a file will download. In Safari, a new tab with the GeoJSON text will open (copy and paste this into TextEdit and save it as “mexico_city_subway.geojson”).

Convert the free and open source data into a shapefile

  1. After you’ve downloaded (via Chrome) or re-saved (Safari) a GeoJSON file of subway data from OpenStreetMap, open QGIS, the free and open source GIS desktop application for Linux, Windows, and Mac.
  2. In QGIS, add the GeoJSON file to the table of contents by either dragging the file in from the Finder (Mac) or Explorer (Windows), or by clicking File>Open and browsing and selecting the file.
  3. Convert it to GeoJSON by right-clicking on the layer in the table of contents and clicking “Save As…”
  4. In the “Save As…” dialog box choose “ESRI Shapefile” from the dropdown menu. Then click “Browse” to find a place to save this file, check “Add saved file to map”, and click the “OK” button.
  5. A new layer will appear in your table of contents. In the map this new layer will be layered directly above your GeoJSON data.
Overpass Turbo screenshot 4

Screenshot 4: The GeoJSON file exported from Overpass Turbo has now been loaded into the QGIS table of contents.

Overpass Turbo screenshot 5

Screenshot 5: In QGIS, right-click the layer, select “Save As…” and set the dialog box to have these settings before clicking OK.

Query for finding subways in your current Overpass Turbo map view

/*
This has been generated by the overpass-turbo wizard.
The original search was:
“railway=subway”
*/
[out:json][timeout:25];
// gather results
(
// query part for: “railway=subway”
node["railway"="subway"]({{bbox}});
way["railway"="subway"]({{bbox}});
relation["railway"="subway"]({{bbox}});
/*relation is for "routes", which are not always
well-defined, so I would ignore it*/
);
// print results
out body;
>;
out skel qt;

I’m on the home stretch for first update to Chicago Offline Bike Map app

Splash screen of the app. 

Since making the first version of the Chicago Offline Bike Map app, a bike map stored in your iOS device and doesn’t need an Internet connection, I’ve made several important changes and added new features. I’ve upgraded twice how train stations will be appearing. I’ve completely changed the way it looks by using jQueryMobile. Also with v0.2 you’ll find more points of interest, locate yourself using the iOS device hardware (results will vary on a variety of hardware and location factors), and zoom to any neighborhood.

I want your help. I want to make a list of at least 20 points of interest. I’ve no qualifications, but this is who I think my target audience is: people who have cycled in Chicago for a while, people who have just started cycling, people who have iOS devices (I will expand to Android eventually), and who know how to use a map.

Current points of interest are:

  • All CTA and Metra stations
  • All neighborhoods
  • Peggy Notebaert Nature Museum
  • Field Museum of Natural History
  • Museum of Science and Industry
  • DuSable Museum
  • Harold Washington Cultural Center
  • Chicago Cultural Center
  • Holography Museum
  • Museum of Contemporary Art
  • Chicago City Hall
  • Chicago Velo Campus
  • Millennium Park Bike Station
  • SAIC Bike Fixit Station

Train stations on the map. 

Excluding train stations and neighborhoods, there are 12 points of interest. What else should I add? (Since posting this I’ve added the three largest libraries: Harold Washington Library Center, Woodson Regional, and Sulzer Regional.)

P.S. I plan to make an Android version of this app, but I have no timeline on that. Follow app development at the app’s Tumblr.

© 2019 Steven Can Plan

Theme by Anders NorénUp ↑