Highway Boundary Documentation
Source: data.gov.uk (2023-04-04)

Highway Boundary. This dataset represents the land Highways England manages as highway. It is derived from Land Registry  Cadastral parcels, Ordnance Survey and HAPMS (Highways England's Pavement Management System). This dataset is indicative, full ownership details can be found through the Land Registry.

17 November 2020 
Registered office Bridge House, 1 Walnut Tree Close, Guildford GU1 4LZ 
Highways England Company Limited registered in England and Wales number xx-xxxx-xxxx 
 
Highways England Open Data 
 
Dataset Name: Highway Boundary (alias RedLine) 
Type: Geographic Information System (GIS) 
 
Background 
 
The highway boundary in this context describes the land belonging to the highway; this 
dataset is limited to Highways England’s road network. This dataset is indicative only, 
the definitive land ownership records will be held at HM Land Registry. An audit 
programme will be carried out by Highways England to confirm the boundary is correct 
(within a reasonable tolerance).  
 
Due to the process involved in creating junctions with local highway authority (LHA) 
roads, land in this dataset may represent LHA highway (owned by Highways England 
but the responsibility of the LHA to maintain). 
 
Surplus land or land held for future projects does not form part of this dataset.  
 
Field Name 
Description 
OBJECTID 
Non-specific ID field. Use to distinguish features but will not be 
carried into future revised datasets 
Category 
Plot type, four categories: 
 
1. “Auto-RedLine” category, created from an automated 
process using Ordnance Survey MasterMap Topography as 
a base. Land is not registered under Highways England’s 
name. For example, but not limited to, unregistered ‘ancient’ 
highway vested in Highways England, or bridge carrying 
highways over a rail line.  
 
2. “HE Title within RedLine” category, created from Land 
Registry Cadastral parcels whose proprietor is Highways 
England or a predecessor. Land in this category is within the 
highway boundary (audited) or meets a certain threshold by 
the algorithm. HM Land Registry data taken in November 
2020.  
 
3. “HE Title outside RedLine” category, created in the same 
way as above but these areas are thought to be outside the 
highway boundary. Land in this category is yet to be 
audited. 
 
 

 
 
 
 
 
17 November 2020 
Registered office Bridge House, 1 Walnut Tree Close, Guildford GU1 4LZ 
Highways England Company Limited registered in England and Wales number xx-xxxx-xxxx 
 
4. “Highways England (Technician) Data” category, created by 
Highways England, digitised land parcels relating to highway 
land that is not registered, not yet registered or un-
registerable. 
 
5. “Road in Tunnel” category, created using tunnel outlines 
from Ordnance Survey MasterMap Topography data. These 
represent tunnels on Highways England’s network. Land is 
not registered under Highways England’s name, but land 
above the tunnel may be in Highways England’s title. Please 
refer to the definitive land ownership records held at HM 
Land Registry. 
Process 
Plot process, three categories: 
 
1. “Automated” category denotes data produced by an 
automated process. These areas are yet to be audited by 
the company. 
 
2. “Audited” category denotes data that has been audited by 
the company. 
 
3. “Technician Data (Awaiting Audit)” category denotes data 
that was created by Highways England but is yet to be 
audited and confirmed as final. 
Confidence 
Plot confidence, three categories: 
 
1. “High” category denotes land that has a high probability of 
being within the RedLine boundary. These areas typically 
are audited or are features that are close to or on the 
highway. 
 
2. “Moderate” category denotes land that is likely to be within 
the highway boundary but is subject to change once the 
area has been audited. 
 
3. “Low” category denotes land that is less likely to be within 
the highway boundary. These plots typically represent 
Highways England registered land that the automated 
process has marked as outside the highway boundary.