1. Oxfordshire DNF Initiatives Dave Simmons David C Simmons GIS Consultants DNF Suppliers briefing February 2006 Local Street Gazetteer Property referencing Buried Services Linear referencing

2. Before DNF, Oxfordshire had... A locally digitised network–out of step with Ordnance Survey data. LLPGs increasingly generating conflicting streets. Poor communication between county/districts. No common county/district GIS base. Drift between UKPMS, EXOR, NSG networks making it very difficult to achieve good asset recording and interoperability....Yet resource intensive in both district and county. Ref: Oxfordshire LSG-DNF Case Study

3. Problems of a mixed gazetteer – different views of streets through parishes and localities ITN - “Banbury Road” NLPG suggests splitting into –Banbury Road - Shipton-on- Cherwell –Banbury Road - Thrupp –Banbury Road - Kidlington –Shipton Bottom NSG may have this split into –Banbury Road - Shipton-on- Cherwell with Thrupp –Banbury Road - Kidlington –(or not split at all) “Banbury Road” is the common access into each property

4. Short links sharing several street names

5. … Streets crossing Boundaries… Example:London Road crosses from Oxford City to South Oxfordshire This boundary does not coincide With any junction (Note – for later- the purple WDM Network which relates to links Rather than boundaries)

6. Building the DNF LSG using ITN Separate genuine highway streets from “property street placeholders” Create "ESUs" from ITN (using it as a DNF Base Reference Network). Identify them using ITN TOID (Link identifier). Formalise communication between districts and county highways. Cooperate with OS to improve ITN (using local input allied with strict OS Survey Rules) Use improved ITN to identify all Highway Streets Use ITN Road Toids (as associated reference information) and associate 1:1 with USRNs *Note: BS7666 revision is encouraging cross-referencing and classification Ref: Oxfordshire DNF-LSG White Paper

7. What is an LLPG Placeholder ? A Street artefact to allow LLPG and LSG to co-exist harmoniously in a “mixed” gazetteer Very often a “Property Group” ( BS DPC part-2 7.5.2 ) Not needed to complete highway network Needed to fill “street slot” in GMS hierarchy Needed to notionally “split” streets over locality, town or admin area without highway junctions (Sometimes) needed to implement PAF “dependent street” in GMS IT ATTRACTS NO WORKS NOTICES

8. A Placeholder- Overmead Green Overmead Green is An area of Housing An LLPG “Street” It is Accessed from 2 named streets 2 unnamed streets (Note: AddressLayer2 gives each property Full natural address A Building Toid An ITN Link Toid)

9. How can DNF help streetworks ? NSG provides USRNs Many of these are nationally understandable especially in urban areas Many are defined locally and not well mapped or widely understood BS7666 part 1 says they are linear and made of Links, but not all are if they have arisen out of BS7666 part 2)… So … Oxfordshire solution – sort them into highway and non-highway Only let notices be raised on Highway Make sure the property attachment to highway is recorded at link level (as in Addresslayer2 ) then you can (often) position works using text in the notices – as in Mayrise - and provide EMPRESS with good information

10. How can DNF help Buried Services? Pipelines connect property and run below and across roads, pavements, junctions… Pipelines can be associated to surface Pipelines can be associated to highway links Thus the impact of works on highway and association between works undertakers can improve…

11. Services around “Overmead Green” Cold Water is blue Gas is Yellow Sometimes they run together Sometimes traffic is not affected How do we best use DNF identifiers to help with coordination and notices?

12. Oxfordshire DNF pilot study area Purpose is investigation, evaluation and presentation of DNF principles across a wide spectrum of data to support inter-operability 20km x 20km area including Oxford City Authorities, agencies, Utilities contributing data Shown at AGI 2005 DNF Forum Exploring the application of DNF architecture…

13. Point Data Eg. A pothole is to be referenced against the transport network. Reference the link to which the point relates using ID + version number. Publish an optional chainage for additional information. Publish an optional offset for lateral position – format to be decided: could be lane number, measure, … Record object-specific attribution. Give the object an ID, version, classification, and X,Y geometry. From DNF Highways Architecture conclusions- 4 Aug 2005

14. The Integrated Oxfordshire Road Management GIS ITN provides the base for … NSG (with potential to support District LLPGs) “EXOR” Maintenance sections “MayRise” Streetworks/Streetlighting sections “WDM” UKPMS Survey sections Goal is to get all data mapped against ITN base and provided as GIS layers for management and public information Using DNF linear architecture to relate to ITN Link, with chainage and offset wherever helpful Preserving as much compatibility as possible with the existing USRNs and WDM /maintenance sections

15. … Streets crossing Boundaries… Example:London Road crosses from Oxford City to South Oxfordshire This boundary does not coincide With any junction (Note – for later- the purple WDM Network which relates to links Rather than boundaries)

16. Key messages - “Highway” World reality? Property occupants use a familiar address for communication All Properties connect to highway links Many Properties connect to service links Some Links form part of named streets Many Links form part of different network views (eg. UKPMS) Street works notified by USRN need to somehow be associated to links – (for coordination and diversion planning) Lighting maintenance uses its own clusters (“streets”) LLPGs use their own property clusters (“streets”) Utility gazetteers use their own pipeline clusters (“streets”) Underground pipes associate to links (traffic impact) and also to surfaces – mutual impact ! DNF can help inter-operability by underpinning and cross- referencing these different world views