science

OpenStreetMap

OpenStreetMap is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand OpenStreetMap rather than just read about it. In short: OpenStreetMap (OSM) 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.

Key takeaways

OpenStreetMap belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect OpenStreetMap to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of OpenStreetMap from memory before moving on to harder problems.

Reference excerpt

OpenStreetMap (OSM) 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

Steve Coast 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 (AND) 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" (SotM) 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 €2.4 million. In 2010, AOL launched an OSM-based version of MapQuest and committed $1 million 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 (together called members). 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 (for instance, a long-distance motorway), 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 OpenStreetMap data primitives are stored and processed in different formats. OpenStreetMap server uses PostgreSQL database, with one table for each data primitive, with individual objects stored as rows. 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.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with OpenStreetMap

Start with the simplest possible case. Write down what OpenStreetMap claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to OpenStreetMap before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about OpenStreetMap ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of OpenStreetMap

In research: OpenStreetMap appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses OpenStreetMap in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: OpenStreetMap is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2004 establishments in the United Kingdom, British websites, Internet properties established in 2004, so understanding it makes those chapters shorter.
In everyday life: Look for OpenStreetMap outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study OpenStreetMap in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what OpenStreetMap means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain OpenStreetMap out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is OpenStreetMap in simple terms?

Why does OpenStreetMap matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study OpenStreetMap?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on OpenStreetMap.