Summary

The summary section contains key information for the ELR, including its limits (generally between junctions or stations) and relationship with other ELRs.

The Route contains details of the the line’s limits, normally expressed by the bounding junctions or stations. Where the ELR forms part of a longer route, the sub-limits are shown in the Section.

Where specific details about the ELR’s status are available, such as closed line or suspect originating data quality, this is noted as Remarks.

For each ELR, two types of map are available:

  • Atlas shows the extent of the ELR and surrounding ELRs in a colour-coded form without any form of background mapping. The atlas maps are geographic, not schematic, and are particularly useful for identifying the ELR arrangement where two or more ELRs are present in a relatively small area, for example FJH (Frodsham Branch).

  • Interactive shows the extent of the ELR with background mapping and markers at 220 yard (i.e. a furlong, hence geofurlong) interval, including the start and end mileages. Interactive maps offers a view of the ELR in a geospatial context, with multi-level map zooming and panning facilities, for example BBM (Bedford Branch). Subject to project funding, future updates may include additional background mapping layers, including satellite imagery.

The Extent entry details the length of the ELR as reported by Network Rail. The length is listed in originating units (miles or kilometres) and the corresponding length in decimal miles and metres are shown for reference. The Measured entry details the computed geographic centre-line length and corresponding computed lengths as per the Extent entry above. It is to be expected that there will be a variance between reported and measured lengths, and these linear variations are noted in brackets in the Measured section.

Examples

  • ELR with a small variance between reported and measured lengths: SBO (Scottish Borders Railway).
  • ELR with a large variance between reported and measured lengths: BML1 (London Waterloo to Weymouth).

The Grouping entry lists any ELRs which are connected to the current ELR and form a longer route. The ELR grouping can be considered as listing relatives of the current ELR. For example, ECM3 (Templehirst Jn to Colton Jn) is part of the East Coast Main Line group from London King’s Cross to Edinburgh Waverley, which is formed of ELRs ECM1 through to ECM9, although they are not physically connected.

The Neighbours entry lists ELRs which are in close proximity geographically to the current ELR. These proximal ELRs may not necessarily be physically connected (i.e. at a junction), thus ELRs which intersect or run adjacent to the current ELR will also be listed. For example, HTM (Shaftholme Flyover) intersects with JCA (Joan Croft Jn to Applehurst Jn), and thus are considered neighbouring ELRs.

The NR Region entry lists which Network Rail region, or regions, the ELR is contained within. An example of an ELR which is location within multiple regions is BKE (Basingstoke Branch).

The TRACKmaps entry lists which book the ELR is present within. Where the ELR is present within multiple books, the book numbers are listed in order of nominal extent per book. For example, NEC2 (Newcastle to Carlisle) is contained within three TRACKmaps books (1, 2, and 4), with the largest portion in book 2 (Eastern). TrackMaps are frequently referred to by their previous name of Quail maps.

Administrative Areas

The geographic position of the ELR is computed at 22 yard intervals and a geospatial analysis is performed to establish which council administrative area the position is contained within. The output of this analysis is then aggregated to produce a table of Administrative Area per mileage extent.

An example of an ELR located within multiple administrative areas is LEC1 (WCML: London Euston to Rugby Trent Valley Jn).

Nearest Place and District

The geographic position of the current ELR is computed at 22 yard intervals and a geospatial analysis is performed to establish the nearest populated place the position is to. The analysis then calculates the distance from each railway geographic position to the centre of this nearest populated place. The output of this analysis is then aggregated to produce a table of Nearest Place (and its corresponding council District) per mileage extent. The table also includes the minimum and maximum distance range for the mileage extent to the nearest place. This gives an indication of the proximity to populated places relative to the railway over the extent of the ELR. The nearest place’s district may differ from the administrative area depending on the proximity of the nearest place to the railway mileage.

The mileage extent of nearest places is naturally shorter in urban areas; for example, ECM1 (ECML: London King’s Cross to Shaftholme Jn) compared to rural areas MBW2 (Middlesbrough to Whitby).

ELRs where the proximity from the railway to the nearest place are large (say, over 1,500 metres) gives an indication they are remote from populated places, for example SAC (Settle to Carlisle Line) and HGL2 (Highland Main Line).

Positional Accuracy Statistics

The positional accuracy statistics give an indication of the high-level accuracy of the ELR and corresponding confidence in the geographic position of its mileages.

The Linear Accuracy section shows how many calibration points (generally mileposts) are available, and their associated statistics based on the reported and measured distance between them.

The Normalised Quarter Miles sections shows the statistics of each calibration segment (generally between quarter mileposts) normalised to a 440 yard length. Where the minimum or maximum values vary significantly from 440 yards, this indicates that there is an increased likelihood of ‘short’ or ’long’ quarter mile sections being present, thus decreasing the computed mileage position accuracy.

The Calibration Segments section shows the maximum distance between calibration segments. Under idealised conditions, this value would be 440 yards, i.e. calibration can be computed for every quarter mile. Where this value is greatly in excess of 440 yards, there is an increased likelihood of poor geographic accuracy of the computed mileage position.

Examples

  • ELR with a ‘good’ linear accuracy and normalised quarter miles — NAB (Neath and Brecon Line).
  • ELR with a ‘short’ and ’long’ distances between quarter mileposts — CAR (Rhymney Branch).
  • ELR with large gap between calibration points — HJS (Saltend Branch).