# OpenStreetMap schema

OS Multi-modal Routing Network (OS MRN) is designed and built in the OpenSteetMap (OSM) schema to facilitate straightforward import into many routing software applications. The OpenStreetMap model has three core data [elements](https://wiki.openstreetmap.org/wiki/Elements): ways, nodes and relations. See [Elements - OpenStreetMap Wiki](https://wiki.openstreetmap.org/wiki/Elements) for more information.

* A way represents a linear feature on the ground. In OS MRN, these are called [Transport Links](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/networks/os-multi-modal-routing-network/os-mrn-overview/feature-types-overview/transport-link-overview.md) and are linear representations of where people can travel along a network.
* A node is a single point in space. In OS MRN, these are called [Transport Nodes](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/networks/os-multi-modal-routing-network/os-mrn-overview/feature-types-overview/transport-node-overview.md) and build up the topology of the network, connecting ways together.
* A relation defines how other elements work together. In OS MRN, these are called [Turn Restrictions ](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/networks/os-multi-modal-routing-network/os-mrn-overview/feature-types-overview/turn-restriction-overview.md)and represent information about turn restrictions.

OSM uses a system of [tags](https://wiki.openstreetmap.org/wiki/Tags) to apply information against different [features](https://wiki.openstreetmap.org/wiki/Map_features). We have taken existing OS network and routing data and mapped this to the OSM schema. We will include all the values from the OSM schema in the [OS MRN code lists](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/networks/os-multi-modal-routing-network/os-mrn-technical-specification/code-lists.md), but not all values are populated in the first release of OS MRN.

Transport Links combine the following existing transport information into one feature type:

* OS NGD Road Links
* OS NGD Path and Connecting Links
* OS NGD Ferry Links
* OS NGD Railway Links
* OS NGD Access Restrictions
* OS NGD Speed data

Transport Nodes combine the following existing transport information and into one feature type:

* OS NGD Road Nodes
* OS NGD Path and Connecting Nodes
* OS NGD Ferry Nodes
* OS NGD Railway Nodes

Turn Restrictions take the existing OS NGD Turn Restrictions.


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