# Hazard

These are locations which are hazardous, and caution should be taken to ensure safe travel. Hazards are usually signed using the warning sign through a red triangle.

A Hazard will reference back to the Roads product through a Node Reference, Point Reference or Multiple Link Reference. For more information on these different types of Network References, see [the common attribution page](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-mastermap-highways-network-routing-and-asset-management-information/os-mastermap-highways-network-routing-and-asset-management-information-technical-specification/common-attribution).

<figure><img src="https://1897589978-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FcNpJpLP8RROUaWVQo5ea%2Fuploads%2FPDQchv0Bq5ZOCcMvwaT5%2F12.jpeg?alt=media" alt="Context diagram for Hazard" width="563"><figcaption><p>Context diagram: Hazard</p></figcaption></figure>

## Hazard attributes

A location where a threat is imposed and caution should be taken.

### id

Unique identifier, for Hazard this is a TOID.

* **Attribute name:** id
* **Type:** CharacterString
* **Size:** 20
* **Multiplicity:** \[1]

### identifier

Uniform Resource Identifier.

* **Attribute name:** identifier
* **Type:** CharacterString
* **Size:** 37
* **Multiplicity:** \[1]

### inspireId

External object identifier of the spatial object.

* **Attribute name:** inspireId
* **Type:** [Identifier](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-mastermap-highways-network-routing-and-asset-management-information/os-mastermap-highways-network-routing-and-asset-management-information-technical-specification/data-types/identifier)
* **Multiplicity:** \[0..1]

### beginLifespanVersion

Date and time at which this version of the spatial object was inserted or changed in the spatial data set. Note: The time part is always set to zero.

* **Attribute name:** beginLifespanVersion
* **Type:** DateTime
* **Multiplicity:** \[1]

### networkRef

Spatial reference of the network-related property.

* **Attribute name:** networkRef
* **Type:** NetworkReference
* **Multiplicity:** \[1..\*]

### validFrom

The time when the transport property started to exist in the real world. Note: The time part is always set to zero.

* **Attribute name:** validFrom
* **Type:** DateTime
* **Multiplicity:** \[1]

### hazard

Classification of the type of risk that applies that may impact choice of route or where caution should be observed.

* **Attribute name:** hazard
* **Type:** [HazardTypeValue](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-mastermap-highways-network-fundamentals/os-mastermap-highways-network-code-lists/hazardtypevalue)
* **Size:** 15
* **Multiplicity:** \[1]

### description

Additional information describing the hazard.

* **Attribute name:** description
* **Type:** CharacterString
* **Size:** 50
* **Multiplicity:** \[0..1]

### reasonForChange

The reason for a change made to a feature.

* **Attribute name:** reasonForChange
* **Type:** [ChangeValue](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-mastermap-highways-network-fundamentals/os-mastermap-highways-network-code-lists/changevalue)
* **Size:** 32
* **Multiplicity:** \[1]