All public GPS tracks ever uploaded to OpenStreetMap are now available for tracing in the iD editor. Click the new “OpenStreetMap GPS traces” option in the background settings panel to reveal an overlay of GPS tracks on the map. You can use it to map roads, check one way streets, or adjust imagery where it is offset.
9 years of OpenStreetMap GPS tracks over Europe
Local knowledge, satellite and aerial imagery, and GPS traces are the source data from which OpenStreetMap is built. GPS traces play an important role in inferring one ways and turn restrictions, adjusting imagery offsets, and mapping areas where imagery is not available. OpenStreetMap’s GPS database is one of the world’s largest public collections of GPS data, and it continues to grow every day.
The iD editor for OpenStreetMap makes it easy to drop a single GPX file onto a browser window and immediately begin tracing it onto the map. The GPS traces overlay layer now makes all public GPS traces uploaded by any user available for mapping.
The intricate detail seen in Europe continues as you zoom in on individual cities and towns. If you scroll over to South Korea, Daejeon has remarkably systematic GPS coverage.
OpenStreetMap GPS tracks in Daejon, South Korea
But just as interesting in their own way are GPS traces that don’t follow roads, like these ones from a cropdusting airplane circling over fields:
GPS patterns of a cropdusting airplane
Misaligned and missing roads
The real utility comes to play when you zoom in and look at the fine detail. In aerial imagery, hilly roads may appear to be a considerable distance from their actual location, while GPS tracks are free from distortion and reveal where the roads really are. A good example is this section of Interstate 15, where the northern carriageway is mapped about 200 feet from its actual location. Now it can be corrected using the new GPS layer.
Identifying imagery misalignment with GPS tracks
The GPS layer can also highlight larger areas of map errors. If you turn on the Locator Overlay on top of the GPS layer, what remains visible underneath is GPS tracks that don’t correspond to a street or highway in OpenStreetMap. Large mismatches between map and GPS jump out, like these sections of US 20 and US 14 where they meet in Greybull, Wyoming.
Offset streets in Greybull Wyoming, highlighted by comparison to GPS data
Streets missing from the map stand out too. Here is a neighborhood in Indianapolis that someone visited with a GPS receiver, but never traced onto the map.
A missing street in Indianapolis, highlighted by GPS data
Color by direction
The color of the GPS tracks helps map and verify one way streets by giving each direction of travel its own hue. In this freeway interchange in Los Angeles, you can see eastbound movement in red, westbound in cyan, northbound in yellow, and southbound in violet.
The GPS layer is color coded by direction, which helps identifying one ways and dual carriageways
Pick the Identifiable or Public option to make your GPS trace show up on the new GPS layer
The layer is deployed on OpenStreetMap Foundation servers – thanks to the Operations Working Group team, who have been essential in launching this new layer.
If you have ever made your own GPS logs, I invite you to share them with OpenStreetMap and help improve the map for everyone else. Don’t worry if someone else has already logged the same street – it’s still useful to have independent verification. If you don’t have any GPS logs but you do have a smartphone, you can download a GPS logging application and start capturing.