> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/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/os-downloads/products/transport-network-portfolio/os-multi-modal-routing-network/os-mrn-technical-specification.md).

# OS MRN Technical Specification

## Product overview

OS Multi-modal Routing Network (OS MRN) provides a fully connected road, rail, path and ferry network across Great Britain Road. It includes turn and vehicle access restrictions, road speed information, and modal change points where you can change transport mode.

## Index

The sub-sections in this technical specification describe the:

* [Feature types](/os-downloads/products/transport-network-portfolio/os-multi-modal-routing-network/os-mrn-technical-specification/feature-types.md) available within the OS MRN product
* [Code lists](/os-downloads/products/transport-network-portfolio/os-multi-modal-routing-network/os-mrn-technical-specification/code-lists.md) used by attributes available in those feature types


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