Once you have your traces in GPX format, you can upload them to openstreetmap.org. Whether you need to upload your traces depends on which editing method you prefer; we'll cover editing in Chapter 5. If you want to use the online editor, Potlatch, you need to upload your traces. If you use a desktop editor such as JOSM or Merkaator, you don't need to upload your traces to use them, but it's still useful to OpenStreetMap as a project if you do.
It's hoped that in the future, the traces can be put to other uses, including automatically generating average speeds for roads, detecting one-way streets and the layout of junctions. This automatic processing isn't yet in place, but the more the data it has to work with (once it's working), the better.
Some editors and applications support direct upload of traces, but the simplest way of adding your traces to OpenStreetMap is via the website. The upload form is at the top of the list of your traces. To find this...