# Trace or import data?

The considerations necessary to determine wether to trace over a dataset to include it in OpenStreetMap or to import the dataset into OSM have to be made on a case by case basis.

### Example SF Building Height Import

[Github](https://github.com/osmlab/sf_building_height_import/), [Wiki](https://wiki.openstreetmap.org/wiki/San_Francisco_Building_Height_Import)

#### Common case for an import with a lot of data already in OSM

1. Compare height from external source for existing OSM buildings
2. Create a changeset file
3. Import using [Tasking Manager](https://tasks.hotosm.org/about)

## Important note

In general, the OpenStreetMap community is **very skeptical** of data imports, due to many years of bad experiences with outdated 'official' datasets in stark contrast to the community's large scale success with [ground truth](https://wiki.openstreetmap.org/wiki/Good_practice#Map_what.27s_on_the_ground) ([Wikipedia](https://en.wikipedia.org/wiki/Ground_truth#Geographical_Information_Systems)) and local community knowledge. Below we're sharing a growing collection of examples for datasets of value to be included in OpenStreetMap and how they were processed. The [OpenStreetMap wiki on import guidelines](https://wiki.openstreetmap.org/wiki/Import/Guidelines) holds much more information on this subject. Here's also the [extensive catalogue of data imports](https://wiki.openstreetmap.org/wiki/Import/Catalogue) into OpenStreetMap.

## Open datasets of value for OSM

| What?                                                                                                     | Why?                                                                                                                                         | Import / trace over                                                                                                       | Further reading                                                                                                                                                                                                                                                                                                                            |
| --------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Trees                                                                                                     | Database of trees in a city are kept to enable management of the entire tree stock for reasons of heritage, aesthetics, planning and safety. | [Import if technical requirements & community buy-in are achieved](https://wiki.openstreetmap.org/wiki/Import/Guidelines) | [wiki on tree registers](https://wiki.openstreetmap.org/wiki/City_tree_registers), [wiki on tree import](https://wiki.openstreetmap.org/wiki/Nice,_France/Trees_Import)                                                                                                                                                                    |
| <p>Location of assets <br>(<em>bus stops, EV charging stations, sensors, monitoring stations...</em>)</p> | To keep track of changing locations, or new locations being added                                                                            | [Import if technical requirements & community buy-in are achieved](https://wiki.openstreetmap.org/wiki/Import/Guidelines) | [wiki Südtirol/SASA bus stop import](https://wiki.openstreetmap.org/wiki/AltoAdige_-_S%C3%BCdtirol/SASA_Bus_Stops_Import), [EV charging stations Norway](https://wiki.openstreetmap.org/wiki/EV_charging_stations_in_Norway), [AU meteorology station import](https://wiki.openstreetmap.org/wiki/Australian_Bureau_Of_Meteorology/Import) |
| Building footprints                                                                                       | building inventory, completeness                                                                                                             | [Import if technical requirements & community buy-in are achieved](https://wiki.openstreetmap.org/wiki/Import/Guidelines) | LA Building imports [wiki documentation](https://wiki.openstreetmap.org/wiki/Los_Angeles,_California/Buildings_Import), [SotM US presentation](https://2016.stateofthemap.us/lets-get-la-on-the-map/)                                                                                                                                      |
| Building heights                                                                                          | building inventory, 3D visualization, completeness                                                                                           | [Import if technical requirements & community buy-in are achieved](https://wiki.openstreetmap.org/wiki/Import/Guidelines) | [SF building heights import](https://wiki.openstreetmap.org/wiki/San_Francisco_Building_Height_Import), [3D DAM Melbourne](https://www.developmentactivity.melbourne.vic.gov.au)                                                                                                                                                           |
| Infrastructure (*roads, bicycle network, etc*)                                                            |                                                                                                                                              | [Import if technical requirements & community buy-in are achieved](https://wiki.openstreetmap.org/wiki/Import/Guidelines) | <https://wiki.openstreetmap.org/wiki/TIGER>                                                                                                                                                                                                                                                                                                |
| **Transit network information**                                                                           | Maintaining in-house transit network data updated by adding new/modified features from OSM                                                   | Trace over to adjust data                                                                                                 | see [Milan case study](https://github.com/mapbox/open-data-openstreetmap/tree/456c6314be590b75043766b6d63f11b0bfa68dd0/Case%20studies/milan.md)                                                                                                                                                                                            |