OpenStreetMap
OpenStreetMap is a map database maintained by a community of volunteers via open collaboration. Contributors collect data from surveys, trace from aerial photo imagery or satellite imagery, and import from other freely licensed geodata sources. OpenStreetMap is freely licensed under the Open Database License and is commonly used to make electronic maps, inform turn-by-turn navigation, and assist in humanitarian aid and data visualisation. OpenStreetMap uses its own data model to store geographical features which can then be exported into other GIS file formats. The OpenStreetMap website itself is an online map, geodata search engine, and editor.
OpenStreetMap was created by Steve Coast in response to the Ordnance Survey, the United Kingdom's national mapping agency, failing to release its data to the public under free licences in 2004. Initially, maps in OSM were created only via GPS traces, but it was quickly populated by importing public domain geographical data such as the U.S. TIGER and by tracing imagery as permitted by source. OpenStreetMap's adoption was accelerated by the development of supporting software and applications and Google Maps' 2012 introduction of pricing.
The database is hosted by the OpenStreetMap Foundation, a non-profit organisation registered in England and Wales, and is funded mostly via donations.
History
founded the project in 2004 while attending University College London, initially focusing on mapping the United Kingdom. In the UK and elsewhere, government-run and tax-funded projects like the Ordnance Survey created massive datasets but declined to freely and widely distribute them. The first contribution was a street that Coast entered in December 2004 after cycling around Regent's Park in London with a GPS tracking unit. In April 2006, the OpenStreetMap Foundation was established to encourage the growth, development and distribution of free geospatial data and provide geospatial data for anybody to use and share.In April 2007, Automotive Navigation Data donated a complete road data set for the Netherlands and trunk road data for India and China to the project. By July 2007, when the first "State of the Map" conference was held, there were 9,000 registered users. In October 2007, OpenStreetMap completed the import of a US Census TIGER road dataset. In December 2007, Oxford University became the first major organisation to use OpenStreetMap data on their main website. Ways to import and export data have continued to grow – by 2008, the project developed tools to export OpenStreetMap data to power portable GPS units, replacing their existing proprietary and out-of-date maps. In March 2008, two founders of CloudMade, a commercial company that uses OpenStreetMap data, announced that they had received venture capital funding of €2.4million. In 2010, AOL launched an OSM-based version of MapQuest and committed $ to increasing OSM's coverage of local communities for its Patch website.
In 2012, the launch of pricing for Google Maps led several prominent websites to switch from their service to OpenStreetMap and other competitors. Chief among these were Foursquare and Craigslist, which adopted OpenStreetMap, and Apple, which ended a contract with Google and launched a self-built mapping platform using TomTom and OpenStreetMap data.
As of 2025, TomTom, Microsoft, Esri and Meta are the highest-tier corporate sponsors of the OpenStreetMap Foundation.
Content
The OSM project aims to collect data about stationary objects throughout the world, including infrastructure and other aspects of the built environment, points of interest, land use and cover classifications, and topography. Map features range in scale from international boundaries to hyperlocal details such as shops and street furniture. Although historically significant features and ongoing construction projects are routinely included in the database, the project's scope is limited to the present day, as opposed to the past or future.Data structure
OSM's data model differs markedly from that of a conventional GIS or CAD system. It is a topological data structure without the formal concept of a layer, allowing thematically diverse data to commingle and interconnect. A map feature or element is modelled as one of three geometric primitives:- A node is a point with a geographic coordinate expressed in the WGS 84 coordinate system. A standalone node represents a point of interest, such as a mountain peak.
- A way is an ordered list of nodes that represents a polyline or polygon, depending on its metadata and whether it forms a closed ring. A way can represent either a linear feature, such as a street or river, or an area, such as a forest, park, parking lot, or lake. Multiple ways can share a node to represent a connection, for instance, a street intersection or a confluence of two rivers. The node itself can simultaneously represent another feature, for example, an entrance that connects a footway to a building. Until 2007, a way was formally composed of explicit segments between pairs of nodes.
- A relation is an ordered list of nodes, ways and other relations. A relation can optionally specify the role of each of its members. Relations form complex geometries or represent abstract relationships among members. Examples include turn restrictions on roads, routes that span several existing ways, and areas with holes. Multiple relations can contain the same member to represent an overlap, for example, a route concurrency or two adjoining political boundaries.
The data structure is defined as part of the OSM API. The current version of the API, v0.6, was released in 2009. A 2023 study found that this version's changes to the relation data structure had the effect of reducing the total number of relations; however, it simultaneously lowered the barrier to creating new relations and spurred the application of relations to new use cases.
"Any tags you like"
OSM manages metadata as a folksonomy. Each element contains key–value pairs, called tags, that identify and describe the feature. A recommended ontology of map features is maintained on a wiki. New tagging schemes can always be proposed by a popular vote of a written proposal in OpenStreetMap wiki, however, there is no requirement to follow this process: editors are free to use any tags they like to describe a feature. There are over 89 million different kinds of tags in use as of June 2017.Coverage
OpenStreetMap data has been favourably compared with proprietary datasources, although as of 2009 data quality varied across the world. A study in 2011 compared OSM data with TomTom for Germany. For car navigation TomTom has 9% more information, while for the entire street network, OSM has 27% more information. In 2011, TriMet, which serves the Portland, Oregon, metropolitan area, found that OSM's street data, consumed through the routing engine OpenTripPlanner and the search engine Apache Solr, yields better results than analogous GIS datasets managed by local government agencies.A 2021 study compared the OpenStreetMap Carto style's symbology to that of the Soviet Union's comprehensive military mapping programme, finding that OSM matched the Soviet maps in coverage of some features such as road infrastructure but gave less prominence to the natural environment.
A study from 2021 found the mean completeness of shop data in the German regions Baden-Württemberg and Saxony to be 88% and 82% respectively. Instead of comparing OSM data to other datasets, the authors looked at how the number of shops developed over time. They then determined the expected number of shops by estimating the saturation level.
According to a 2024 study using PyPSA, OSM has the most detailed and up-to-date publicly available coverage of the European high-voltage electrical grid, comparable to official data from the European Network of Transmission System Operators for Electricity.
License
All data added to the project needs to have a licence compatible with the Open Data Commons Open Database Licence. This can include out-of-copyright information, public domain or other licences. Software used in the production and presentation of OpenStreetMap data may have separate licensing terms.OpenStreetMap data and derived tiles were originally published under the Creative Commons Attribution-ShareAlike licence with the intention of promoting free use and redistribution of the data. In September 2012, the licence was changed to the ODbL in order to define its bearing on data rather than representation more specifically. As part of this relicensing process, some of the map data was removed from the public distribution. This included all data contributed by members that did not agree to the new licensing terms, as well as all subsequent edits to those affected objects. It also included any data contributed based on input data that was not compatible with the new terms.
Estimates suggested that over 97% of data would be retained globally, but certain regions would be affected more than others, such as in Australia where 24 to 84% of objects would be retained, depending on the type of object. Ultimately, more than 99% of the data was retained, with Australia and Poland being the countries most severely affected by the change. The license change and resulting deletions prompted a group of dissenting mappers to establish Free Open Street Map, a fork of OSM that remained under the previous license.
Map tiles provided by the OpenStreetMap project were licensed under CC-BY-SA-2.0 until 1 August 2020. The ODbL license requires attribution to be attached to maps produced from OpenStreetMap data, but does not require that any particular license be applied to those maps. "©OpenStreetMap Contributors" with link to ODbL copyright page as attribution requirement is used on the site.