The National Street Gazetteer holds Additional Street Data (ASD), which is collected and managed alongside the information provided from Local Address Gazetteers. ASD provides extra information about a street, mostly to make sure streetworks are efficient.
There are four types of ASD:
- type 61 Interest Records
- type 62 Construction Records
- type 64 Height, Weight and Width Restrictions
- type 63 Special Designation Records
Special Designation Records
Special Designation Records exist to help define the special attributes of a street. This includes data to determine:
- traffic sensitive streets
- streets with special engineering difficulties
- speed limit data
- level crossing safety zones
- environmentally sensitive areas
- streets with special surfaces
- streets with priority lanes
- streets with special construction needs
- height, weight and width restrictions
- direction restrictions
