KMLStep by Step

Curvature file for New York State as shown in Google Earth.

Curvature file for New York State as shown in Google Earth.

For an overview of how Curvature can fit into your trip planning, see How to Use. This page will detail the mechanics of viewing the downloadable KML files.

The Curvature program generates map files that can be viewed in Google Earth. These map files are generated for all regions of the world and are refreshed every month or so to take into account updates to the underlying data sourced from the Open Street Map.

Step 1: Install Google Earth

To view Curvature KML files, you will first need to install Google Earth on your computer. Google Earth is a free program available for both desktop computers as well as mobile devices.

Step 2: Download a Curvature KML file

Head to to download a compressed KML file for your region. Most people will want to download the “c_1000” version of the files as these highlight only the most twisty roads — those with approximately 1km or more of curves.

The KML files are ordered by continent, country, and state/province.

Click on the “c_1000” link to download the file to your computer, usually it will end up in a “Downloads” folder on your computer.


Step 3: Open the KML file in Google Earth

Find the KML file in your downloads folder, it will be named something like “vermont.c_1000.kmz”.

Double-click on it to open it in Google Earth. If for some reason it doesn’t open, first open Google Earth and choose “File » Open…” and select the file.

Open in Google Earth

4. Look for curvy roads

After you’ve opened the file in Google Earth you can zoom around and identify curvy roads:

The "vermont.c_1000.kmz" file loaded in Google Earth.

The “vermont.c_1000.kmz” file loaded in Google Earth.

Clicking on a road will pop up details indicating any surface tags for each segment as well as length and ‘curvature’:

Clicking on a highlighted road will pull up details.

Clicking on a highlighted road will pull up details.

Step 5: Plan your route

Google Earth doesn’t have great built-in route-planning tools, so it is usually easiest to simply identify the curvy roads via the Curvature files in Google Earth, then plan your route using other route-planning software such as Garmin Base Camp, Google Maps, or similar.

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