It not only helps to add new roads to unmapped areas but also assist in calibrating existing maps and re-align the roads in the current maps.

However, to be useful and accurate, it's essential to have a very accurate tracklog.

To achieve this,

  1. If possible, set your GPS unit to record 1 sec tracklog or if using distance - 1 metre interval.
  2. If this is not available on your unit, just use the "Most often" option.
  3. If you have an external antennae and able to use it, that's even better for accuracy and robustness of signal.
  4. Do not save the tracklog - ie leave it as active tracklog as it will be left in it's "Raw" state. My understanding is when you save an active tracklog, Garmin GPS units generalises the points and removes the details when saving to compress file size which defeats the purpose of 1sec or 1m tracking.
  5. If you have a "X series or Extreme series" GPS unit like the Garmin 60 0r 76 Cx/CSx or the eTrex X series or HcX series units, set your unit to record tracklogs directly to your micro SD card.
  6. Extract/download this data from the card into your computer using the "USB Mode" and zip it then upload it here directly (it should be in a gpx format).
  7. Ensure that "Lock on Road" setting on your GPS unit is set to OFF.

See also Edit