Western North American Road Intersection Point Download

Help and support Tagging help & support
1

Hello,

I am a research scientist at the University of California Santa Barbara.

I am researching wildfire resilience and as part of this work we would like to use point data for every intersection in the Western US and Canada.

What is the best way for me to download every intersection in this study area as a lat lon point (or something similar; node)?

I can use programming languages (python/R) and the API’s. I’m just not an expert on how the data is stored in OSM and how best to extract it.

Thanks all for your support!

Best,
Carlo Broderick

4

Hello,

It’s pretty straightforward using overpass.

You can try this query, which I simplified and generalized from a more specific example on the wiki doc.

It search for all ways with highway tags for roads, and then look for the nodes connecting at least three of those. The request runs fine on a small area, not sure for wider. It looks for intersections in the bounding box based on the current map view. You can look in an area (like a county or something) instead of the bbox, you’ll find examples on the wiki, or using the assistant.

The list of highway= values is on the relevant page. You probably want to exclude service roads as it add a lot of data.

Regards.

2

Some probably helpful pointers:

  • Overpass - for doing geospatial queries for small to medium portions of data
  • Data extracts - these ones are daily updated and broken into subregions so you can do processings as you like
  • PBF format - the format for the extract files.
  • Loading OSM into PostGIS - a lot of projects stand up their own geodatabase, usually with a subset from the extracts

There’s lots of other things but hopefully that helps get your feet under you.

3

Sounds like you are doing similar work to Geoff Boeing Street Network Models and Indicators for Every Urban Area in the World – Geoff Boeing It might be worth looking at GitHub - gboeing/osmnx: OSMnx is a Python package to easily download, model, analyze, and visualize street networks and other geospatial features from OpenStreetMap.