I wanted to share what has proven to be a very valuable resource for data, which comes to me via Sam Matthews (mapsam.com): Overpass Turbo — http://overpass-turbo.eu/
It can look a bit intimidating, but it's pretty easy to work with. Go click the "Wizard" button, and then type in a query like "highway = trunk." It will grab the data and show every major highway on the map on the right. It pulls data for whatever area you've got shown on the right-side map. To download, click "Export"
Today, I needed all the major roads in a county. Normally, I can find a government dataset that either has a) every single road ever, or b) just the main highways. I needed something in-between those, and all I had to do was go to Overpass Turbo, and in the wizard do a query of "highway = motorway OR highway = trunk OR highway = primary" and it pulled the top 3 levels of roads for me. I downloaded them, kicked them in to Arc, and I'm on my way to my map. No need to sort through TIGER data picking out the roads I want.
You can make use of more than just roads data. Anything OSM has can be grabbed. Consult the handy feature list for stuff you can download: http://wiki.openstre...ki/Map_Features
Pretty handy stuff. If you want to get fancy, you can access the Overpass API with your own scripts, but if you don't know anything about scripting, or just don't care to make one, Overpass Turbo makes it easy to just look around and download what you want.
- Hans van der Maarel, Mike Boruta and Anton van Tetering like this