Using OpenStreetMap Quality Assurance Tools

Ian LopezDecember 2013

What are “Quality Assurance Tools” in the

OpenStreetMap context?

According to the OpenStreetMap Wiki, Quality assurance tools “help lead to better quality of OSM data. Often, the tools achieve

this by providing a list of bugs in the data, which mappers can then go and fix using

editing tools. The bugs are either automatically detected based on rules and data analysis, or the tools provide a means

of manually reporting them, or some combination of the two. There are many

different ideas for how to do this, and what kind of bugs to focus on, hence many

different tools. ”

It means that those tools help improve OpenStreetMap data by looking for and

identifying various errors, whether automatically or from on-the-ground

surveys. Once identified and connected, errors can be fixed.

There are various tools that identify various types of errors.

Some QA Tools used by PH-based OSM contributors:

NotesNotes, a feature in the OSM website, is used to improve OSM

data by adding details that can be added by more experienced OpenStreetMap contributors.

It is similar to OpenStreetBugs in many aspects (ability to create or comment anonymously, allows everyone to report

cartographically-relevant information for OSMers to act upon)

To add a note, click the bottom tool bar button on the right side of the main OSM map. Then, leave a short message on

the map if something is missing or obviously wrong, like “new residential road starts here" or “restaurant closed, replaced

by a barber shop". Add the message understandably and thoughtfully. In some cases, you may have to be specific

(Example: new bakery along X Avenue between 54th and 56th Streets).

Notes about notes: Do not add personal notes using this feature.

A screenshot showing a recently-added note

Keep RightKeep Right checks for data consistencies in OSM data. It

checks on the following:

•Highways that do not intersect•Highways and waterways that intersect (without a bridge or

tunnel tag)•Overlapping ways•Geometry glitches•Turn restrictions•Missing tags

•FIXME-tagged items•Intersections without junctions

A screenshot showing various errors and issues in Keep Right

Validator (JOSM Plugin)Validator used to be a JOSM plugin, but is now an integral part of JOSM. It’s a feature that checks and fixes invalid map data.

It checks on and fixes the following:

•Duplicated nodes and ways•Self-intersecting ways•Overlapping ways•Crossing ways•Turn restrictions•Missing tags

•FIXME-tagged items•Intersections without junctions

•Untagged ways

A screenshot showing JOSM’s Validator in action

OSM InspectorOSM Inspector is a web based debugging tool for advanced

OpenStreetMap users offered by Geofabrik, a German company that specializes in cartography. It shows layers specializing in different views, like routing, tagging and

geometry. However, some layers like addresses, boundaries and public transportation are limited to Europe. Some countries like Netherlands, Austria and Germany have

specialized layers connected with data imports.

A screenshot showing OSM Inspector

Other QA Tools used by PH-based OSM contributors:

Attributions• Slide 1: Map of UP Los Baños, Laguna. Taken from http://tools.geofabrik.de/map/?

type=Geofabrik_Topo&lon=121.24150&lat=14.16223&zoom=16• OpenStreetBugs screenshot from http://mapperz.blogspot.com/2009/01/open-street-bugs-good-

reporter.html• Information taken from various OpenStreetMap Wiki articles: OpenStreetBugs, Notes, OSM Inspector• Other screenshots created by Ian Lopez