You are in: Rob's OSM Stuff » UK PRoW » Progress

Public Rights of Way Progress

County Parishes RoWs LTotal LMapped % GIS Update
Cambridgeshire 233 4089 3218 km 568 km 17% 2017‑05‑04
Hampshire 273 7263 4592 km 241 km 5% 2017‑09‑05
Hertfordshire 137 5363 3138 km 721 km 22% 2017‑04‑05
Isle of Wight 20 1430 856 km 863 km 100% 2017‑07‑21
Norfolk 546 5726 3841 km 3183 km 82% 2017‑03‑16
Oxfordshire 322 5936 4208 km 435 km 10% 2016‑10‑17
Suffolk 484 10397 5730 km 1325 km 23% 2018‑01‑10
Warwickshire 18 3280 2835 km 92 km 3% 2017‑10‑23

About this tool

This tool takes information about Public Rights of Way from four sources and flags up possible errors / omissions / things to check. Currently only a handful of counties are available, but hopefully more will be added in due course. The data sources are:

  1. Official GIS data from County Councils. Many councils now digial versions of the legal 'Definitive Map' document they are obliged to maintain. The data includes vector routes, path numbers, designations, lengths and bounding boxes are extracted automatically from data files. I've started using the files from Barry Cornelius's rowmaps for this, as Barry's already done the hard work in converting the myriad of different formats from the councils into a standard KML format.
  2. Volunteer-Mapped data from OpenStreetMap. Path numbers, designations, lengths, bounding boxes, last update details, etc. can be extracted automatically on a parish by parish basis using the XAPI. The tool will extract all ways with a prow_ref=* tag within the parish's bounding box. The data from OSM is updated on a rolling basis with each parish getting an update roughly once a week. There is a button at the bottom of each parish page to request a quicker update.
  3. Definitive Statements. These are written documents providing textural desciptions of each Public Right of Way. Some councils have only paper records, but many now have digital versions. Sometimes these are unstructured formatted text documents (and so data needs to be manually extrated) but other councils have databases or spreadsheets (which allow automatic extraction of route numbers and statuses.
  4. Manual classification of OSM completion level. This would be entered by tool users, after comparing the official data with the curernt mapping in OSM.

I've got scripts to do the extraction from first two sources set up, but I currently have to initiate the updates manually. I can do the third and fourth behind the scenes, but eventually the plan is to have a public Web interface.

With the data the tool can then flag up issues such as:

The tool is currently under development, so various key bits of functionality are not implemented yet. For details see the Known Issues and To Do List.

Suggested uses for OSM Mapping

However, please do not use the PRoW GIS data alone to map routes in OSM. The dat may not be completely accuarate or well-aligned, and it is important that we capture the physical presence and accessibility of routes on the groud too. Simply copying the Council's GIS data into OSM adds very little to the map. Correctly mapping a path with the condition of the surface, adjacent hedges, gates and stiles is much more useful. See also my advice for routes not following the definitive line.

Adding new authorities

I intend to add more areas as and when I have time to do so. The main constraints though are having access to the data and it being available for re-use under a suitable licence for use in OpenStreetMap. The basic requirements are:

It is also useful if the authority makes available its Definitive Statements, List of Streets and a list of Traffic Regulation Orders affecting Public Rights of Way. See my Council PRoW Open Data page for an incomplete list of what is available from each authority.