Localities and their Stops Guidance
Written by: Peter Day
Date: 25th August 2006
Version Number: 0.4 (Draft)
- This note is intended to provide guidance to traveline regions/local authorities as to how localities should be defined and stops assigned to localities. The link between stops and localities is important to Transport Direct (TD) and will determine whether appropriate journey legs are selected and how stops are named in journey plans (including those derived from the National Coach Services Database (NCSD)).
- The previous guidance, incorporated in the Creation of NPTG Guidance Note, described how to create NPTG entries from the source ONS data. The guidance is being updated to both reflect the fact that the creation process has been completed and also to be consistent with the guidance in this Note. That Guide focuses on how the user maintains NPTG locality data.
- The NaPTAN Viewer is the best means of identifying localities and the assignment of stops to localities - examples in this Note use screenshots from the Viewer. Information on how to use the Viewer is available on the Thales/JourneyWeb website.
- The link is established in the NaPTAN stop record when completing the NatGazID field. Each stop must have a primary locality. Within a NaPTAN record the stop code will be defined to include a link to a NPTG locality, as follows:
|ATCO stop reference
||Stop OSGRs, names etc ...
||Nat Gaz ID
||Canal Street etc in Chester
||St Joseph's Convent etc in Stafford
||Old London Road etc in Dorking
- Localities starting with E were in the original ONS dataset and those starting with N have been created since then. Localities can be viewed and edited in the NPTG - the following is an extract from the local authority's NPTG entries, showing E0057329, Chester, from the first example above:
Definition of Locality
- A locality is a named area in which someone would claim to live or work when talking to someone outside the local area. Such named areas are also likely to be present on road direction signs. In general an urban locality is expected to have a radius of less than 2km - and probably will contain no more than 10,000 residents. A parent locality will typically have a radius greater than 2km. Small urban localities should be avoided unless they are clearly defined areas with a distinctive area name. The existence of too many localities in small towns is currently a feature of the NPTG. Equally, some rural areas have localities for farms and small clusters of buildings, which would not be consistent with the definition guidance.
- These Notes can only provide guidance and not precise rules for the definition of localities - local factors will determine what is most appropriate. The examples included can only provide indications of good and bad practice, rather than definitive statements.
- The centre of a locality is defined by the grid reference, which meets the following conditions:
- It must be at the generally accepted commercial centre of a place with that name (the place where an ordinary user would consider to be 'that place');
- It must be close to a local public transport stop (NaPTAN point) if there is one to serve that locality (but there will be localities that have no NaPTAN points because they have no public transport services);
- It must not be randomly positioned at the geographical centre of the area;
- It should not be placed within a pedestrianised area of a commercial centre, instead it should be placed on or close to a road available to all traffic.
An example of a locality in an appropriate position, containing a reasonable number of localities follows. This could be improved by assigning those stops on the outskirts of Chichester to a nearby locality (see later section):
In this example, and others that follow, the following symbols and representations are important:
A locality is shown in blue when it has been selected for display.
- In the normal course of events a locality should represent a named settlement and there should be a locality for every city, town, suburb or district, village or hamlet.
The following example shows potentially too many localities for an urban area. There are a number of localities in close proximity, a proportion without stops assigned to them and the overall result is unlikely to enhance journey planning.
The following example is one where there are potentially too many rural localities clustered together. Several represent relatively small clusters of buildings or an isolated area not readily accessible.
- Localities should not normally be created for places that are simply points of interest - data for such places is held in a separate gazetteer - although some large "areas of interest" (large campuses, for instance) may justify a locality in their own name. There should normally, therefore, be no localities for bus stations or rail stations, hospitals, prisons, sporting venues, colleges etc. Many region call centres and web sites have the capability to use additional local gazetteers to hold points of interest data. Transport Direct and several traveline regions use points of interest data supplied by PointX and this is available to all traveline regions if they want to use it.
- If there are two or more localities with the same name these need to be distinguished by use of a qualifier (shown in brackets after the locality). If the localities are in different administrative areas (as defined by the 3 digit authority code) a standardised short version of the administrative area name is normally used as the qualifier. If the localities are in the same administrative area the nearest town of any significance is used as the qualifier - preferably preceded by "nr" if the locality is near but not contained by the town, but without this prefix if the qualified locality is contained by the referenced town. So "Church End (Haddenham)" is a case where Church End is part of Haddenham, whilst "Church End (nr Chorleywood) lies outside the town of Chorleywood.
- The importance of qualifiers can be seen from the full list of NPTG Church End localities:
- A locality can sit within a hierarchy of localities - a hierarchy will make it easier for localities to be found, particularly in urban areas. The TD Gazetteer will display a locality's parent and grandparent (if created) thus making it clear where the locality can be found within the authority. In some urban areas it may be appropriate to define the city or town centre as a child locality - in this case the city centre locality should not have precisely the same OSGR as its parent locality (a minimum of 5 metres variation in each direction is suggested to ensure clarity of presentation on maps).
- The examples below show both approaches to town or city centres. In the example with a Town Centre locality, the OSGRs of the parent Town and child Town Centre are offset by a small distance and journey planning results would not be different travelling to either the Town or Town Centre locality. In the example without a Town Centre locality the parent Town locality serves as the centre. Considerations in using either approach include the simplification of gazetteer information (removing any ambiguity between the town and town centre localities), other uses this data may be put to and regional journey planner requirements for effective planning.
- The hierarchy is created within the NPTG. TD encourages the use of hierarchies, but not to the extent that searching for a locality becomes over-complicated by too many child and grandchild localities. This should take account of local circumstances rather than according to any specific rules about breadth and depth of hierarchies. A locality in a hierarchy must be contained by its parent and grandparent - a village near a town is not contained, and therefore cannot form part of the town's hierarchy.
Assigning Stops to Localities
- A stop should be assigned initially to a locality on the basis of containment - any stops falling within the physical area of the locality should be assigned to it. Where stops lie between one or more localities a decision on which is the best choice has to be made locally, e.g. taking into account the name of the stop, the presence of physical barriers (e.g. avoiding stops either side of a river or estuary) and local knowledge and understanding. It is also possible to define alternate localities for stops - see section below.
- The standard construction of stop names within TD is locality, street, common name, identifier. Street can be omitted if required. This preferred structure should be taken into account when assigning stops to localities.
- A stop in an urban area, therefore, would typically be associated with the suburb or district child locality, i.e. at the lowest level of the hierarchy. It is also possible for the parent locality to have stops assigned to it, since it will represent the city or town centre (when a separate child locality for the city centre is not defined) and/or areas of the locality which do not have a separate area identity.
- It is acceptable for a locality not to have any stops assigned to it - this may be inevitable in rural areas. The locality is still required to be in NPTG to support other modes of journey planning within Transport Direct and other systems making use of NPTG data.
- No two stops should have the same OSGR and it is recommended that no stop should have the same OSGR as its locality (primarily to ensure map displays are as clear as possible).
- When re-assigning stops between localities, note that a locality cannot be de-activated in NPTG (i.e. excluded from the dataset) if stops are currently assigned to it. The stops must be re-assigned first, before the locality can be de-activated and removed. Active localities are those included in the NPTG.
Errors in assigning stops can be easily identified using the Viewer, for example:
- Some localities may be given alternate names - this is defined in the NPTG (and the locality given a separate ID) and stops are then automatically linked additionally to both (or all, if there is more than one alternate) names. Alternate names can be defined for a different language - particularly relevant in Wales and parts of Scotland, as in the following example.
|Alternate Name (Qualifier Name)
||Primary Name ID
||Primary Name (Qualifier Name)
|Llanbedr Pont Steffan
- An individual stop can be assigned to one or more additional localities, when the stop cannot be clearly placed in a single locality. If an alternate locality is required, this is defined in the local system used by authorities to maintain stop data and exported to the national database as an associated file. In general it is expected that the alternate locality for a stop would be at the same level in any hierarchy as the prime locality, unless local circumstances dictate otherwise.
|Access to NPTG Data: http://www.journeyweb.org.uk/ng.htm (User ID & password required for authorised users to edit data, available from Thales)
|NaPTAN Viewer: http://www.transportdirect.info/naptanviewer (User ID & password required to access the Viewer, available to authorised users from Thales)
|NPTG - Creation of NPTG Guidance Note: http://www.journeyweb.org.uk/guidance_notes.htm
|NaPTAN Schema: Latest version available on http://www.naptan.org.uk