What value does it bring to the user?

Currently, Underpass is able to perform geospatial and semantic validation for the following issues:

• Un-squared buildings (not necessarily wrong, but a good indicator of poor quality mapping)
• Wrong symbols (spaces, quotes, single quotes) on tag's key
• Empty or wrong values for tags (based on a customizable list of valid tags)
• Required tags

But we want to add a more complete set of basic quality checks. The list is still to be defined, but some of them are:

• Overlapping features
• Duplicated features
• Roads not connected to anything
• Single node ways

All of these evaluations will be performed in near real-time, as the map data is updated (every ~1 minute), and displayed on the web using a map, a list of features, and progress bars for indicating the amount of quality issues found, enabling users to have a more complete evaluation of quality.