Reviewing your edits
The easiest way to fix common mapping issues is to use the inbuilt validator in JOSM. All edits made in a session are automatically validated and a warning will be displayed before upload if any suspicious data is found.
- Select the data you want validated and press
Validatefrom the Validator panel. If no data is selected, the Validator will run on all the data in the active layer.
- A Validation errors layer will be added to your Layers to highlight features with errors.
- The Validation Results panel will display all the detected errors. Select any of the detected errors to fix. You can right click an entry and zoom to the location if needed.
The Validation Results have several buttons activated to navigate and fix errors:
- Select – Select the objects of the selected error.
- Lookup – Looks up the selected primitives in the error list.
- Validation – Start validation process for current selection or all objects (when nothing selected).
- Fix – Fix an error (only when automatically fixable).
- Ignore – Ignore an error or a group of errors in future tests.
Customizing error detection
By default the validator checks against a wide range of data issues, many of which may not be important or may contain false positives. You can customize the settings from Preferences > Data Validator
You can quickly query and visualize OSM data live using Overpass Turbo.
- Browse the map to the area of interest or alternatively set a bounding box using the map tool on the left.
- Write an Overpass Query in the query editor or use the Wizard for simple tag queries like
highway=motorway or highway=trunk
- Optionally add a MapCSS style to visualize the results
Runto execute the query on the OSM data and display the results. Tip: By default small ways are rendered as circles. To fix this check the
Don't display small features as POIsoption from
Settings > Map