User:Historicbruno

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Interests

Some of my mapping interests:

  • Adding detail to urban areas: sidewalks, crosswalks, parking zones, stop lights, amenities (mail boxes, bike stands, water fountains, trash cans, benches)
  • Correcting and updating roadways: especially bridges/overpasses, rectifying names (mass imported data e.g. TIGER is often very suspect), speed limits, stop signs
  • Waterways: many rivers and streams are missing from OSM data; I start with the largest rivers, but I often branch out into tributaries and even some ditches/drains
    • Can be very important in navigation, as informal directions are often given in terms such as "take first left after crossing the creek".
    • Often point me to other useful updates such as roads and bridges. One can easily find roads that don't exist or have incorrect paths, bridges that have washed away, etc.
  • Lakes, ponds, dams
  • Hiking trails, parks
  • Railways
  • Power plants and associated infrastructure: lines, towers, poles, substations

Normally I work within a single area before moving on, and try to limit each changeset to one of the above categories for ease of review.

Conventions

Some conventions I follow:

Highways

For highways, I prefer to follow the physical layout of the road as closely as possible. This means a single divided highway (with a median) will be two one-way highways in OSM, linked with a Relation:route. In my experience, this makes e.g. intersections much easier to map accurately. I try to map with GPS navigation in mind.

Waterways

I use Tag:waterway=river and Tag:waterway=stream to distinguish waterways based on relative width. Typically a river will be tagged as such from its mouth to some point upstream, where the flow is reduced that I considered it a stream. Sometimes this detail is shown on USGS topographical maps.

Each waterway contains the name (if any) and a Tag:waterway. Multiple ways are linked together in an ordered Relation:waterway containing both the name and various other data: etymology, wiki links, and the destination body of water. The relation should be ordered so each member is connected to the next with no gaps.

For rivers that flow through a larger body of water, such as a lake, my convention is to draw an approximate path of the river from inlet to outlet. Often a USGS topographical map will aid in this. Dams, culverts, and other manmade channels of water along the path are also added to the waterway relation.

Changesets

Minimal changesets with a single purpose. For example, I might update and add a number of interconnected waterways as a single changset. Other related changes, e.g. bridges, culverts, dams, roadways, go into other changesets. This is a convention I carry over from programming :)

Where to start?

At least within the US, I find two approaches useful:

  • Begin with your own town or city. For the novice. You can either perform surveys yourself, using such tools as e.g. Vespucci and Mapillary, or compare existng OSM data with Aerial imagery. Highways are among the more complicated concepts in OSM, and essential for GPS navigation, so I recommend going slowly with those. Initially, it can be easier to focus on local buildings, business information, amenities, parks, etc. Living in the area, it's easy to verify and use personal knowledge in your mapping. Another approach is using an OSM-based navigation tool, such as OsmAnd, and finding where it gives incomplete or incorrect directions.
  • Begin with USGS topographical maps. For the more intermediate user. Many areas of the country are very sparsely mapped in OSM. A large area of OSM data might contain only a handful of state/local highways, with minimal natural or manmade details. USGS data can reveal OSM incompleteness in natural features such as waterways. Waterways often pass through towns and cities, are crossed by state, local and private highways, and thus can lead to many undermapped areas of the country. Beware that the maps included in some editors such as JOSM are scans of old print maps, and thus are prone to being outdated (by decades). So these should be thought as more guidelines than an absolute reference. The USGS website has more updated data sources available.

I prefer to manually introduce data, rather than importing from external data sources, although I often convert GIS shapefiles to OSM format and use them as non-uploaded layers for reference. Example: working on highways, I like to keep a state-wide layer of National Bridge Inventory data; if working on waterways, I keep a state-wide layer of National Hydrography Database data. Storing these layers locally as OSM files prevents a lengthy conversion process, although the data will still need to be parsed and rendered (may take several minutes and require GBs of memory for larger datasets). Hiding layers can greatly improve editor responsiveness with large datasets.

QGIS is an efficient tool for manipulating GIS shapefiles, especially large datasets at the state and national level, where conventional OSM editors are too sluggish. I've used it to merge multiple NHD shapefiles (e.g. flowlines) into a single file.

Overpass API snippets

Some of these might be useful for me (to remember) or for others to discover.

Find all waterways (e.g. rivers) within a state

This is useful for working on lots of waterways, without loading "too much" data at once: 

/* Note: timeout might be too low for large datasets. */
[timeout:25][bbox:{{bbox}}];
{{geocodeArea:Kentucky, United States}}->.kyArea;
(
    way["waterway"](area.kyArea);
    relation["waterway"](area.kyArea);
);
out body;
>;
out skel qt;

Links

USA

Kentucky

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