OpenLR location referencing

1.1. What is OpenLR™?

OpenLR™ is a method for map agnostic location. It enables systems to communicate location information when they use dissimilar maps.

OpenLR™ is communication channel independent. OpenLR™ requires minimal bandwidth for data communication.

OpenLR™ was designed to transfer location information from traffic information systems used by traffic management centers to portable navigation devices and systems. While it achieves this goal, it is also quite versatile. The encoded locations are typically specific road stretches, lists of connected roads, point locations or areas. Generally, OpenLR™ is unrestricted for encoding the location of traffic information. Further application areas include ADAS applications and online routing.

1.2. Licensing, Open Source

The goal of OpenLR™ is to be widely adopted by the at-large industry. Therefore, it is proposed as an open standard in an Open Source framework. It is usable for anyone using locations that are transmitted between systems that have dissimilar maps.

OpenLR™ focuses on area, line, and point locations. It is owned by the OpenLR Association. The standard was developed by TomTom International B.V., though everyone may contribute to its further development.

1.3. Key business and technical benefits of OpenLR™

OpenLR™ has the following business and technical benefits:

  • It is an open industry standard that is available royalty-free

  • It is an Open Source Model based on an Apache license v2.0

  • The OpenLR™ Trade Mark is available to use free of charge with the technology

  • It is a map-agnostic dynamic location referencing method

  • It is applicable to the full road network, including secondary and urban roads

  • It is compact

  • It supports various transport formats; some are bandwidth efficient and some are XML

2. Documents

The following are useful documents for learning more about OpenLR™:

3. FAQs

This section provides answers to frequently asked questions about OpenLR™ in the areas of General, License, Testing, Contribution and Usage.

3.1. General

What are (other / new) application areas for OpenLR™?

The suggested or possible application areas for OpenLR™ might be:

  • The exchange of data between traffic management centers

  • Collecting static and dynamic map update data from road operators and governments (such as speed limit information updates, planned road works, incidents, and so on.)

  • Cooperative systems currently in research phase (vehicle to infrastructure systems) where vehicles communicate with infrastructure, (for example, creating dynamic green waves

  • eCall where a Public Service Answering Point receives automatically a message of an accident, with information on the accident, car and driver

  • Vehicle-to-vehicle communication for various safety applications

This list is non-exhaustive and thanks to the open source model of OpenLR™, new system requirements can be quickly incorporated in an enhanced standard.

3.2. License

What are the conditions of using OpenLR™?

OpenLR™ is available on the basis of the "copyleft" principle that allows programmers to contribute to improvements and maintenance of the "open standard". The utilized open source license Apache version 2 permits the use of the library in proprietary programs. The white paper describing the technique behind OpenLR™ is available under a Creative Commons license. The source code is published "as is": no warranty is given by any of the initiators or contributors to the initiative to any user of the code. The license to partners asserting patents is withdrawn as the license is subject to a non-assertion clause.

3.3. Testing

Has OpenLR™ been tested (on large scale) in any applications? Are there any quality values available?

The TomTom implementation was tested with encoding and decoding in a TomTom environment with different maps from different versions and different vendors. The tests used line locations being covered by TMC (Traffic Message Channel) and also on non-TMC roads. More information on Traffic Message Channel is found at https://en.wikipedia.org/wiki/Traffic_message_channel. The test results cover the accuracy of the OpenLR™ method and the code size: success rates for randomly selected location and with maps from same vendor are above 98% with more than 50% error detection rates and above 96% for cross map vendor with error detection rates also above 50%. TMC road stretches show a higher success rate. The average size is 16-20 Bytes per location.

3.4. Contribution

How can I contribute?

We greatly appreciate your contributions to OpenLR™. You can access the code at https://github.com/tomtom-international/openlr

Where can I report issues?

You can post issues at https://github.com/tomtom-international/openlr

3.5. Usage

Can the encoder and decoder be used on any map?

OpenLR™ is a map-agnostic location referencing method, which means that the respective encoder and decoder can operate on map databases with different versions or from different vendors.

Can it work on Google Maps, OpenStreetMap and others?

A map from one of the major brands used for navigation (navigable map) should be sufficient. OpenLR™ does not favor any particular map brand. As an encoding and decoding method it is technically not biased.

You are using FRC map attribute for encoding. Does OpenLR™ work against different map vendor releases when there are different FRC types?

OpenLR™ uses its own mapping table scheme for FRC (Functional Road Class) that allows its own FRC mapping table to address differences if the maps are used from different vendors.

How much development time is required to implement OpenLR™?

The amount of development time necessary to implement OpenLR™ varies. It is determined by your own development and testing required to determine if the technology meets the requirements of the application. There is no cost involved for licenses to use the technology.

Traffic Information

OpenLR is used in Traffic Management Centers for encoding of traffic event locations. Receivers are decoding the location on the device.

ADAS applications

OpenLR is used to transmit a route from the navigation system towards an electronic horizon provider working with a separate, more detailed map. The provider can use the extracted route in order to built-up the electronic horizon along the most probable path which typically extends along the current route.

Online Routing

Online routing services use OpenLR to transmit routes from the cloud to client devices.


More information about the OpenLR location referencing method and developer information can be found on openlr.org