> 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-overview/feature-types-overview/turn-restriction-overview.md).
# Turn Restriction overview
{% hint style="info" %}
The information on this page supplements that of the [Turn Restriction](/os-downloads/products/transport-network-portfolio/os-multi-modal-routing-network/os-mrn-technical-specification/feature-types/turn-restriction.md) page in the [technical specification](/os-downloads/products/transport-network-portfolio/os-multi-modal-routing-network/os-mrn-technical-specification.md). Please read the two pages in conjunction for a complete understanding of the feature type.
{% endhint %}
A Turn Restriction provides line geometry that indicates turn restrictions for the given Transport Link (for example No right turn or No U turn).
Where the Turn Restriction applies to specific vehicle type (for example, bus or HGV), this is identified by the corresponding separate attribute as described below, along with conditional values for when the turn restriction only exists on specific times or days.
The Turn Restriction is attributed with the OSID of the corresponding OS parent feature that is published in the OS Transport RAMI Collection.
Turn Restrictions are named following a *from-to-via* pattern, where:
* *from* is the wayid of the first Transport Link involved in the turn restriction.
* *to* is the wayid of the last Transport Link involved in the turn restriction.
* *via* is the nodeid of the Transport Node at the junction (when there are only two links involved in the turn restriction), or a wayid list of all the Transport Links which are not the *from* or *to* link (when there are more than two links involved in the turn restriction).
Example map showing 5 Turn Restrictions
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