computer science

Open Source Routing Machine

Open Source Routing Machine is a computer 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 Open Source Routing Machine rather than just read about it. In short: The Open Source Routing Machine (abbreviated OSRM) is an open-source route planning library and network service. Written in high-performance C++, OSRM runs on the Linux, FreeBSD, Windows, and macOS platforms.

Key takeaways

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

Reference excerpt

The Open Source Routing Machine (abbreviated OSRM) is an open-source route planning library and network service. Written in high-performance C++, OSRM runs on the Linux, FreeBSD, Windows, and macOS platforms. It is designed for compatibility with OpenStreetMap's road network data. FOSSGIS operates a free-to-use server that powers walking, cycling, and driving directions on OSM's homepage.

History OSRM powered Mapbox's navigation offerings during the 2010s. OSRM participated in the 2011 Google Summer of Code. In February 2015, OSRM was integrated into OpenStreetMap's homepage alongside two other routing engines, GraphHopper and Valhalla. In 2025, a team at Roskilde University and the University of Waterloo used OSRM to solve the travelling salesman problem for a dataset of 81,998 bars from South Korea's National Police Agency, breaking a record set in 2021.

Architecture OSRM implements multilevel Dijkstra's algorithm (MLD) as well as another routing algorithm, contraction hierarchies (CH), which is better suited for very large distance matrices. Shortest path computation on a continental sized network can take up to several seconds if it is done without a so-called speedup-technique. Via the CH preprocessing pipeline, OSRM can compute and output a shortest path between any origin and destination within a few milliseconds, whereby the pure route computation takes much less time. Most effort is spent in annotating the route and transmitting the geometry over the network. This high performance facilitates use cases such as user-interactive route manipulation. In addition to solving the shortest path problem for road networks, OSRM also includes a map matching service and a travelling salesman problem solver for generating distance matrices.

References

As of 18 May 2012, this article is derived in whole or in part from Open Source Routing Machine. The copyright holder has licensed the content in a manner that permits reuse under CC BY-SA 3.0 and GFDL. All relevant terms must be followed.

Further reading Vetter, Christian; Luxen, Dennis (2011). "MoNav & OSRM: 1 Jahr später" (PDF). Legato.net (in German). pp. 42–43. Archived from the original (PDF) on October 5, 2014. Retrieved May 16, 2012. Hubel, Andreas (November 15, 2011). "Webbrowserbasierte Indoor-Navigation für mobile Endgeräte auf Basis der OpenStreetMap" (PDF). Andreas-hubel.de (in German). pp. 7–8. Archived from the original (PDF) on December 22, 2015. Retrieved May 16, 2012. Vetter, Christian; Luxen, Dennis (November 6, 2011). "Real-time routing with OpenStreetMap data". Proceedings of the 19th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems. Association for Computing Machinery. pp. 513–516. doi:10.1145/2093973.2094062. ISBN 9781450310314. S2CID 7289832. Retrieved February 5, 2013.

External links Project homepage Demonstration from the project's homepage Project-OSRM on GitHub Open Source Routing Machine on X

Illustrations

Worked examples

Example 1 — a first encounter with Open Source Routing Machine

Start with the simplest possible case. Write down what Open Source Routing Machine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer 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 Open Source Routing Machine 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 Open Source Routing Machine 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 Open Source Routing Machine

In research: Open Source Routing Machine appears in computer 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 Open Source Routing Machine 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: Open Source Routing Machine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Free and open-source software stubs, Free software programmed in C++, OpenStreetMap, so understanding it makes those chapters shorter.
In everyday life: Look for Open Source Routing Machine 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 Open Source Routing Machine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Open Source Routing Machine 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 Open Source Routing Machine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Open Source Routing Machine in simple terms?

Why does Open Source Routing Machine matter?

Because it connects several computer 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 Open Source Routing Machine?

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 Open Source Routing Machine.