> For the complete documentation index, see [llms.txt](https://docs.os.uk/osngd/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/osngd/using-os-ngd-data/os-ngd-transport/transport-networks-in-the-os-ngd/road-network.md). # Road network This page covers the Road Link and Road Node Feature Types of the OS Transport Network Collection. These feature types form the core part of the OS road network. ## Road Link and Road Node Feature Types The [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) and [Road Node](/osngd/data-structure/transport/transport-network/road-node.md) Feature Types make up the core part of the OS road network: * **Road Links** are line features usually representing the centreline of a road. Each Road Link will provide a reference to the Road Nodes at the start and end of the Road Link in the [Start Node](/osngd/data-structure/transport/transport-network/road-link.md#startnode) and [End Node](/osngd/data-structure/transport/transport-network/road-link.md#endnode) attributes, respectively. * **Road Nodes** are point features providing network connectivity between Road Links. Road Nodes break up the road network at road ends, junctions, places where a Road Link changes character or name, and where a Road Link crosses another link (either a Path Link or a Road Link) at a different level. Road Links will split where two links cross over or under one another but there is no connectivity between the two, for example, at bridges and flyovers. The [Start Grade Separation](/osngd/data-structure/transport/transport-network/road-link.md#startgradeseparation) and [End Grade Separation](/osngd/data-structure/transport/transport-network/road-link.md#endgradeseparation) attributes will indicate where there is or is not a physical connection between the roads in the real world. Grade separation will determine if a Road Link is above another; if the two Road Links, when referencing the same Road Node, have different grade separation attribute values, then it's not possible to move between them at that point. Where a Road Link crosses a Path Link at a different level, both the Road Link and Path Link will split. Attribution on Road Links includes the name and classification of the road, whether it is a trunk road or primary route, directionality, elevation gain and width. Road Links only represent the centreline of a road carriageway and are not polygons representing the extent or limits of the carriageway; this information can be found in the [Road Track Or Path Feature Type](/osngd/data-structure/transport/transport-features/road-track-or-path.md). Road Links provide a link to the Road Track Or Path polygon that represents the same part of road through the [Road Track Or Path Reference table](/osngd/data-structure/transport/transport-network/road-link.md#road-track-or-path-reference). ### Links to and from Road Link and Road Node Other feature types in the OS NGD Transport Theme reference Road Links to either tell you further information or allow you to build a network. The following table describes all the links to and from Road Link and Road Node within the OS NGD Transport Theme: | Source Feature Type | Foreign Key Attribute | Destination Feature Type | | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------------- | ---------------------------------------------------------------------------------------------- | | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | `startnode` | [Road Node](/osngd/data-structure/transport/transport-network/road-node.md) | | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | `endnode` | [Road Node](/osngd/data-structure/transport/transport-network/road-node.md) | | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md#road-track-or-path-reference) (Road Track Or Path Reference) | `roadtrackorpathid` | [Road Track Or Path](/osngd/data-structure/transport/transport-features/road-track-or-path.md) | | [Street](/osngd/data-structure/transport/transport-network/street.md#road-link-reference) (Road Link Reference) | `roadlinkid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Road](/osngd/data-structure/transport/transport-network/road.md#road-link-reference) (Road Link Reference) | `roadlinkid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Average And Indicative Speed](/osngd/data-structure/transport/rami/average-and-indicative-speed.md) | `osid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Highway Dedication ](/osngd/data-structure/transport/rami/highway-dedication.md#highway-dedication-network-reference)(Highway Dedication Network Reference) | `networkreferenceid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Restriction](/osngd/data-structure/transport/rami/restriction.md#restriction-network-reference) (Restriction Network Reference) | `networkreferenceid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Routing Hazard](/osngd/data-structure/transport/rami/routing-hazard.md#routing-hazard-network-reference) (Routing Hazard Network Reference) | `networkreferenceid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Routing Structure](/osngd/data-structure/transport/rami/routingstructure.md#routing-structure-network-reference) (Routing Structure Network Reference) | `networkreferenceid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Connecting Node](/osngd/data-structure/transport/transport-network/connecting-node.md) | `roadlinkid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Tram On Road](/osngd/data-structure/transport/transport-network/tram-on-road.md) | `roadlinkid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Bus Lane](/osngd/data-structure/transport/transport-network/bus-lane.md) | `linkid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Cycle Lane](/osngd/data-structure/transport/transport-network/cycle-lane.md) | `linkid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Street Light](/osngd/data-structure/transport/transport-features/street-light.md) | `linkid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Pavement Link](/osngd/data-structure/transport/transport-network/pavement-link.md) | `roadlinkid` | [Road Link](/osngd/data-structure/transport/transport-network/road-link.md) | | [Road Node](/osngd/data-structure/transport/transport-network/road-node.md#road-track-or-path-reference) (Road Track Or Path Reference) | `roadtrackorpathid` | [Road Track Or Path](/osngd/data-structure/transport/transport-features/road-track-or-path.md) | | [Road Junction](/osngd/data-structure/transport/transport-network/road-junction.md#road-node-reference) (Road Node Reference) | `roadnodeid` | [Road Node](/osngd/data-structure/transport/transport-network/road-node.md) | | [Ferry Terminal](/osngd/data-structure/transport/transport-network/ferry-terminal.md) | `roadnodeid` | [Road Node](/osngd/data-structure/transport/transport-network/road-node.md) | | [Restriction](/osngd/data-structure/transport/rami/restriction.md#restriction-network-reference) (Restriction Network Reference) | `networkreferenceid` | [Road Node](/osngd/data-structure/transport/transport-network/road-node.md) | | [Routing Hazard](/osngd/data-structure/transport/rami/routing-hazard.md#routing-hazard-network-reference) (Routing Hazard Network Reference) | `networkreferenceid` | [Road Node](/osngd/data-structure/transport/transport-network/road-node.md) | | [Routing Structure](/osngd/data-structure/transport/rami/routingstructure.md#routing-structure-network-reference) (Routing Structure Network Reference) | `networkreferenceid` | [Road Node](/osngd/data-structure/transport/transport-network/road-node.md) | {% hint style="info" %} ## Building a more complete routing network Road Links and Road Nodes alone do not provide you with all the information needed to truly route along the road network. To build a more complete routing picture, you'll also need to use the Routing Hazard, Routing Structure, Restriction, and Average And Indicative Speed Feature Types from the OS Routing and Asset Management (RAMI) Collection; see the [Routing information page](/osngd/using-os-ngd-data/os-ngd-transport/transport-networks-in-the-os-ngd/routing-information.md) for details about these four feature types. {% endhint %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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