Becoming a power mapper

---

title: Reviewing your edits

JOSM Validator

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.

Usage

• Select the data you want validated and press Shift+V or hit Validate from 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

For more details check the OSM Wiki and the LearnOSM Guide

Overpass Turbo

You can quickly query and visualize OSM data live using Overpass Turbo.

Usage

• 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
• Hit Run to 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 POIs option from Settings > Map

For more details check the OSM Wiki, Learn Overpass or some common example queries.

---

title: JOSM shortcuts

As you draw using the JOSM editor, or correct map errors on to-fix, keyboard shortcuts can save help you save a great deal of time and increase the quality of your mapping [strokes replaced] if used correctly. Here we'll cover keyboard shortcuts on JOSM - default settings, how you can customize these to suit your preferences, and shortcuts most popular with the data team.

Use the JOSM cheatsheet by user:baditaflorin

Basic Shortcuts [Default]

By default, the JOSM editor comes pre-loaded with approximately 100+ shortcuts which cover everything from downloading/uploading map data from the OpenStreetMap server, adding/editing/deleting tags, validating results, and working with nodes, ways, and polygons. See the Common Keyboard Shortcuts on the JOSM wiki for more details.

Under Tools on the menu bar, you can see some of the basic default shortcuts on JOSM

The default shortcuts on JOSM are a great way to get started, but once you are familiar and start speed mapping, you may want to consider customizing the JOSM shortcuts to fit your mapping preferences. For example, you can customize shortcuts to allow you to map quickly without having to take your right hand off the mouse.

Action	Keyboard Shortcut
Uploading the edit	</kbd><!---->
Downloading data	Q
Deleting data	D

To access the Shortcuts Menu, go to Preferences on the JOSM menu bar. Within Preferences, click Options on the left (seventh button).

Here is a comprehensive categorized list of shortcuts everyone should be familiar with.

JOSM Shortcuts

DATA

ACTION	DESCRIPTION	Mac	Win/Linux
OPEN	open a file	Cmd+O
SAVE	save current data	Cmd+S
DATA DOWNLOAD	download map data from OSM server	Cmd+Shift+Down
DATA UPLOAD	upload all changes in the active data layer to the OSM server	Cmd+Shift+Up

---

Basic map editing

ACTION	DESCRIPTION	Mac	Win/Linux
SELECTION	select, move, scale, and rotate objects	S	S
NODES	draw nodes	A	A
BUILDINGS	draw building	B	B
DRAW	fast drawing mode	Shift + F
ZOOM	zoom and move map	Z	Z
DELETE	delete nodes or ways	Cmd + D
SPLIT WAY	split a way at a selected node	P	P
COMBINE WAY	combine several ways into one	C	C
REVERSE WAY	reverse the direction of all selected ways	R	R
SIMPLIFY WAY	delete unnecessary nodes from a way	Shift+Y
ALIGN NODES IN CIRCLE	move the selected nodes into a circle	O	O
ALIGN NODES IN LINE	move the selected nodes into a line	L	L
MIRROR	mirror selected nodes and ways	Shift+M
FOLLOW LINE	continues drawing a line that shares nodes with another line	F	F
ADD NODE	add a node by adding latitude/longitude or easting/northing	Shift+D
CREATE CIRCLE	create a circle from three selected nodes	Shift+O
MERGE NODES	merge nodes into the oldest one	M	M
JOIN NODE TO WAY	include a node into the nearest way segment	J	J
MOVE NODE INTO WAY	move node into the nearest way segments and include it	N	N
DISCONNECT NODE FROM WAY	disconnect nodes from a way they currently belong to	Alt+J
UNGLUE WAYS	duplicate nodes that are used by multiple ways	G	G
JOIN OVERLAPPING AREAS	join areas that overlap each other	Shift+J
CREATE MULTIPOLYGON	create a multipolygon	Cmd + B
UPDATE MULTIPOLYGON	update a multipolygon	Cmd+Shift+B

---

Accuracy & precision

ACTION	DESCRIPTION	SHORTCUT
PARALLEL WAYS	make parallel copies of ways	Shift+P
WAY ACCURACY	improve the accuracy of ways	W
ORTHOGONALIZE SHAPE	move nodes so all angles are 90 or 180 degrees	Q
DISTRIBUTE NODES	distribute the selected nodes to equal distances along a line	Shift+B
EXTRUSION	create areas	X
BUILDING SIZE	set building size	Cmd+Alt+B

---

Presets

ACTION	DESCRIPTION	SHORTCUT
SEARCH PRESETS	show preset search dialogue	F3

User interface

ACTION	DESCRIPTION	SHORTCUT
PREFERENCES	open a preferences dialogue for global settings	Cmd + ,
LAYERS WINDOW	open a list of all loaded layers	Alt+Shift+L
TAGS/MEMBERSHP WINDOW	open tags window for selected objects	Alt+Shift+P
SELECTION WINDOW	open a selection list window	Alt+Shift+T
RELATIONS WINDOW	open a list of all relations	Alt+Shift+R
WIREFRAME VIEW	enable/disable rendering the map as wireframe only	Cmd+W

---

Imagery

ACTION	DESCRIPTION	SHORTCUT
IMAGERY OFFSET	download offset for current imagery from a server	Cmd+Alt+I

---

Conflicts resolution

ACTION	DESCRIPTION	SHORTCUT
CHECK AUTHOR	open list of people working on a selected object	Alt+Shift+A
RESOLVE CONFLICT	resolve a conflict	Alt+Shift+C

---

Review/validation

ACTION	DESCRIPTION	SHORTCUT
CHANGESET MANAGER	toggle visibility of changeset manager window	Cmd+Alt+C
VALIDATION WINDOW	open validation window	Alt+Shift+V
VALIDATE	performs data validation	Shift+V
FILTERS	filter objects and hide/disable them	Alt+Shift+F
HISTORY JOSM	check history of an object	Ctrl+H
HISTORY WEB	check the history of object on web	Cmd+Shift+H

---

title: Saving and loading a JOSM session

It is possible to save a JOSM session similar most GIS software (in QGIS we call it a project file). The JOSM session saves your current map view, OSM data and loaded layers such as imagery.

The JOSM session is available in File menu. You need to be in Expert mode to access this feature.
To activate Expert mode, go to JOSM Preferences, activate Expert mode by clicking the checkbox.

Saving a JOSM session

Load any of your preferred layers in JOSM.
Save the JOSM session file clicking, File > Session > Save session as ... Select any layers you want loaded when you start a new JOSM session.

Loading a JOSM session

To load a previously saved JOSM session, click File > Session > Load session. Select the .jos you saved.

NOTE: Do not save any OSM data within your .jos file. Always load new data to avoid data conflicts.

Examples of session files we use in the /mapping repo.

---

title: Reverting changes

• https://help.openstreetmap.org/questions/731/how-can-i-revert-a-changeset
• http://wiki.openstreetmap.org/wiki/JOSM/Plugins/Reverter

---

title: Advanced JOSM customization

Hidden settings in JOSM can be configured directly from the advanced preferences panel. This also gives you access to export and import your configuration profiles.

The panel is hidden by default and is shown as the last option when Expert mode is enabled.

Note JOSM will need to be restarted for any changes to take effect.

---

title: Advanced mapping guide

Roads

Neighborhood grid

Residential buildings are usually located on a residential or living_street and has access to a road only on one side, and optionally on the backside via a service alleyway. A building with residential roads on multiple sides is a sign of mistaking building shadows for streets. The street grid in an an area will have repeating patterns that make it easy to guess how the roads are laid even if they are obscured by trees.

Using Fast draw plugin

• Install and use Fast draw plugin (shift + F).
• Press down arrow to simplify way, up arrow to add more complexity and then Enter.
• Q to simplify straight segments of roads.
• Shortcuts to tag each type of road classification Preferences > Customize the icons in the toolbar > Presets > highways/ features that require shortcut > highways/streets > select the road you want to add as shortcut > right click on the shortcut and add a shortcut.

Video Faster draw in JOSM

Buildings

• Parallel buildings can be traced using the building tools plugin (B). Select a building and using the tool align subsequent buildings to the first one in one step.

• You can use the Area extrude tool (x), to quickly add details to the outlines by creating new nodes (double click) and then dragging the faces.

• Compound buildings To combine overlapping buildings, select both building and click Join overlapping Areas (Shift + J). For several intersecting buildings, use I > Shift+J. Or, use the Auto Tools > Combine LA buildings.

• In Extrusion mode (X), do Ctrl + Cmd to redraw/reshape buildings for irregularly shaped buildings.

• In Extrusion mode (X), add four nodes in a segment, hold the Ctrl + Cmd key, and drag the middle segment to create pyramidal extrusions.

• Double tap A to draw buildings with irregular sized extrusions. Or create several smaller buildings

• For buildings sharing the same wall, draw buildings (B) and, select intersecting node and click Join Node to a Way (J) or Move Node unto Way (N).

• To split a single building into two, select two nodes and select Split Object (Alt + X)

• Use Terracer plugin for multiple same shaped buildings sharing the same wall (Shift + T)

• For circular features, draw the diameter, select the way, and click Tools > Create Circle (Shift + O).

• Use Resize tool (Ctrl + Alt) to re-size shape.

Videos

• Drawing different types of buildings
• Tracing touching buildings in JOSM

Others

Individual parking spaces

Draw a box enclosing the parking spaces and use the terracer plugin to create a grid. Replace the default building=yes tag with amenity=parking_space. If you created adjacent grids, you would want to use the validator to automatically merge the overlapping nodes.

Tagging driveway through a building

Relevant tagging option for building would be

building=roof and layer=1

Highway road under the roof tagging options

covered=yes
highway=footway
highway=residential
highway=service

Tagging stadium tracks

Relevant tagging option for Stadium would be

• trace centerline of track as line (leisure=track;area=no)
• connect centerlines with surrounding foot paths or streets where possible

---

title: Fixing common mapping issues

Identifying common mistakes made by mappers for road network and knowing how to fix them is important to improve the quality of the map. If you spot mistakes which needs major fixing, send a friendly message on the users' changeset on what is wrong and how it could be fixed. You can use this guide as a reference while fixing data errors in JOSM.

Highway errors

Issue	Whats wrong	How to fix it	Tips
Overlapping ways	A highway which run over itself or another way with the exact same road classification. (Note the arrows on the selected way)	Run validator shift+V —> Among validator errors/warnings select Overlapping ways —> Delete the overlapping way, make sure there are no gaps or missing pieces left behind.
Untagged Ways	Ways with no tags associated with the geometry	Run validator shift+V —> Among validator errors/warnings select Untagged ways —> Select individual ways and add appropriate highway tags	Refer OpenStreetMap wiki on highway tagging schema
Crossing ways	The ways (with highway/railway/waterway tags) that crosses in same layer with no crossing/intersecting node	Run validator shift+V —> Among validator errors/warnings select Crossing ways —> shift+I to add the intersecting node	Install utilsplugin2 to get advanced intersection modeling features. Refer to this guide for JOSM shortcuts.
Self-intersecting ways	A highway which intersects itself, possibly sharing same nodes at intersection.	Run validator shift+V —> Among validator errors/warnings select Self-intersecting way —> Split using shortcut (P) at the intersection (common node) and delete the segment which is intersecting the highway
Way end node near other highway	A highway node which ends near to other highways but dont connect each other.	Run validator shift+V —> Among validator errors/warnings select Way end node near other highway —> Select individual node and press shift+J to form the connection.
Add layer=1 for bridges	If there is a lot bridges without layer=1 tag, you can filter bridges easily.	Go to every bridge and look into imagery for it's layers (layer=1, layer=2 etc) and add	OSM Wiki on bridge
Add junction=roundabout		Add junction=roundabout for circle	OSM Wiki for roundabout
Possibility to improve alignment		Use W to align the lines/polygons to the imagery

Non-Highway errors

---

title: Useful Overpass queries

Newer than a given date

{% raw %}
[out:xml][timeout:600];
(
  way["highway"](newer:"2015-05-30T07:00:00Z")({{bbox}});
);
out body;
>;
out skel qt;
{% endraw %}

Changes in a given time period

{% raw %}
[out:xml][timeout:600];
(
  way["highway"](changed:"2015-05-14T07:00:00Z","2015-05-30T07:01:00Z")({{bbox}});
);
out body;
>;
out skel qt;
{% endraw %}

Provide two dates and generate a difference between the two

{% raw %}
[diff: "2015-06-30T15:00:00Z","2015-09-21T15:00:00Z"][out:xml][timeout:25];
(
  way["highway"]({{bbox}});
);
out body;
>;
out skel qt;
{% endraw %}

Extract edits of a user

{% raw %}
[out:json][timeout:25];
(
  node(user:"ramyaragupathy")({{bbox}});
  way(user:"ramyaragupathy")({{bbox}});
  relation(user:"ramyaragupathy")({{bbox}});
);
out body;
>;
out skel qt;
{% endraw %}

Extract a particular tag

{% raw %}
[out:json][timeout:25];
(
  node["amenity"="hospital"]({{bbox}});
  way["amenity"="hospital"]({{bbox}});
  relation["amenity"="hospital"]({{bbox}});
);
out body;
>;
out skel qt;
{% endraw %}

Extract all amenities

{% raw %}
[out:json][timeout:25];
(
  node["amenity"]({{bbox}});
  way["amenity"]({{bbox}});
  relation["amenity"]({{bbox}});
);
out body;
>;
out skel qt;
{% endraw %}

Find a particular tag without someother key value

{% raw %}
[out:json][timeout:25];
(
  node["highway"="footway"]["footway"!~"."]({{bbox}});
  way["highway"="footway"]["footway"!~"."]({{bbox}});
  relation["highway"="footway"]["footway"!~"."]({{bbox}});
);
out body;
>;
out skel qt;
{% endraw %}

Query within query

{% raw %}
[out:json][timeout:250];
(
  (
    way({{bbox}})[highway='primary'];
    relation({{bbox}})[highway='primary'];
  )->.a;
  node.a[name='Sand Hill Road'];
);
out body;
>;
out skel qt;
{% endraw %}

Search for a tag in an area

{% raw %}
[out:json][timeout:250];
(
  area[name="Palo Alto"];
  way(area)["building"];
  relation(area)["building"];
);
out body;
>;
out skel qt;
{% endraw %}

---

title: Useful OSM resources

The OSM ecosystem has an array of tools that you can use to extract, modify, visualize data, and contribute to!

Mapping

• OSM Map features
• Taginfo - tagging stats

Survey tools

• Fieldpapers for paper based surveying
• Mapillary for crowdsourcing streetview imagery

Tasking Tools

• To-fix
• Map Roulette
• Map tasking manager for coordinating mapping in a continuos area

Data

• Awesome GeoJSON - list of some awesome tools around GeoJSON
• Overpass Turbo for querying OSM by properties
• GeoJSON.io for creating / editing GeoJSON data
• Dropchop for GIS based actions
• Flatten GeoJSON attributes Converter
• Merge GeoJSONs
• Minjur for converting large OSM data to GeoJSON
• tippecanoe Builds vector tilesets from large collections of GeoJSON features
• Collection of useful GeoJSON tools
• toGeoJSON toGeoJSON turns KML & GPX into GeoJSON

Visualization

• OSM Changes Visualization
• Compare OSM and Google Maps

Extracts

• OSM planet extracts
• Geofabrik region extracts
• Mapzen metro extracts
• OSM QA Tiles

QA and Activity Tracking

• OSM Inspector
• WHODIDIT OpenStreetMap Changeset Analyzer
• Heatmap

For full list check the OSM Wiki

Community

• Use the history tab on the map to find and message active mappers nearby
• Write on your OSM Diaries to bring up issues for community discussion
• Join your local community mailing list for discussions on various topics
• Who is around me? Find local mappers

Contribute

• To the OSM Homepage
• To the development of the OSM map style and cartography
• By publishing your tool on osmlab
• OSM wiki: Contribute

Guides and FAQ

• OSM wiki FAQ
• OSM help
• LearnOSM mapping guides
• HOT OSM tracing guides
• Mapbox Guides
• State of Satellite imagery
• Satellite and Sensor Database