Imposm parser for OpenStreetMap QA tiles
An [imposm parser](https://github.com/omniscale/imposm) for [OSM QA tiles](https://osmlab.github.io/osm-qa-tiles/). osmqa-parser was written for use with [tile-reduce-py](https://github.com/jwass/tile-reduce-py) and [osmgraph](https://github.com/mapkin/osmgraph).
The parser should be used with an imposm importer such as the one found in osmgraph.
Data Model Caveats
OSM QA tiles are delivered as [Mapbox Vector Tiles](https://www.mapbox.com/developers/vector-tiles/). It is impossible to exactly reconstruct the original OSM data from a vector tile.
Because ways in a QA tile contain a coordinate sequence instead of a node sequence, we can’t distinguish different nodes that have the same tile coordinate. osmqa-parser assigns unique node IDs based on tile coordinate. As a result, it’s possible we introduce false intersections which arise when two ways have different nodes that have the same coordinates. Also, different nodes that fall on the same tile coordinate will have identical node IDs, which usually means their tags are merged together as one.