> 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/bus-lanes/how-bus-lane-data-are-created.md). # How bus lane data are created Information on how OS creates bus lane data. ## How does OS source bus lane data? Bus Lane data are sourced from OS aerial imagery, for OS built-up areas only. Where Bus Lane features are not visible from aerial imagery (for example, where they are obscured by tree cover), these will not be included; please see [known limitations](/osngd/using-os-ngd-data/os-ngd-transport/bus-lanes/known-limitations.md) for more information on completeness limitations for bus lane data. ## How are Bus Lane features linked to Road Link features? An algorithm is used to link a Bus Lane feature to a Road Link. This algorithm uses a buffer from the Bus Lane feature and analyses the angle of Road Links within that buffer to determine which Road Link the Bus Lane feature is alongside. This is then referenced in the Link ID attribute. In order to provide a one-to-one relationship between Bus Lane features and Road Link features, bus lanes are split into links in line with Road and Path Link geometry. --- # 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 by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.os.uk/osngd/using-os-ngd-data/os-ngd-transport/bus-lanes/how-bus-lane-data-are-created.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.