[Talk-GB] Summer quarterly project

SK53 sk53.osm at gmail.com
Tue Sep 13 11:32:47 UTC 2016

My comments on both suggestions:

   - Speed Limits: a little bit boring, *BUT *there are some relatively
   achievable targets. For instance getting all primary & trunk roads with
   speed limits. There are areas of the country where none of these roads have
   limits, but even in well mapped places there is a considerable amount of
   simple tidying up (missing speed limits on roundabouts or short sections)
   which can be done. A further advantage is that major roads are also more
   likely to have Mapillary/OpenStreetView coverage. Additionally things like
   number of lanes, availability of pavements etc can be added as well whilst
   reviewing speed limits. I noticed this a few weeks ago because back in
   September last year I drove to Bewdley & waypointed changes of speed limits
   on the A456 from Hagley to Kidderminster.

   One additional caveat is that speed limits on the narrower roads are
   changing a lot: national speed limits to 50, 50 mph down to 40 mph, etc.
   I've noticed this particularly along the A606 as travel this by bus about
   once a year when I take more mapping notes.

   I have put a map based on this <http://overpass-turbo.eu/s/imj>
   Overpass-turbo query on Flickr <https://flic.kr/p/LJuZiC> for trunk
   roads missing speed limits, and one for primary roads in the East Midlands
   here <https://flic.kr/p/M1tzcj>. The latter query
   <http://overpass-turbo.eu/s/imi> returns too much data for the whole of
   the country but can be tailored by changing the area part of the query.

   - Food Hygiene data. This would be in two forms: enrichment of existing
   OSM data (primarily with addresses); and surveying areas which have lots of
   FHRS data but little in OSM.

   The former is a valuable, but not particularly gripping activity. IIRC
   the FHRS data covers somewhere between 10-15% of total postcodes, and just
   having one address in a postcode can help resolve many adjacent ones. Two
   addresses and one can infer properties of how addresses are allocated on a

   Last year Peter Reed wrote a long series of blog posts
   about retail data and used Super Output Areas to predict volumes of missing
   data from OSM. Last year I targeted Melton Mowbray, Coalville, Havant and
   Chichester for mapping of the town centres based on this data. More
   recently I've done Hoylake & New Brighton. I'd hoped to have a look at
   Hyde, Tameside at the weekend, but was too tired by the end of the field
   meeting. Most towns in Greater Manchester are ripe for this kind of
   mapping: Oldham, Rochdale, Hyde, Denton, Ashton-under-Lyme and many others.
   In the past I have used a set of postcode centroids denoting places with
   missing data to help target the mapping. More recently I have munged the
   FHRS data by distributing all places sharing a postcode on a circle of
   10-20 m radius and created GPX files for particular areas: with each FHRS
   category having a different symbol.

   A town the size of Melton Mowbray took around 90 minutes to do a photo
   survey. Adding the data to OSM rather longer. Stockport, another, larger,
   retail centre, which I have now surveyed in 2015 & 2016, took about 3 hours
   altogether. Some of this was duplicated, and in part was because the
   Merseyway Shopping Centre closed before I got round it on my first visit. A
   second visit is useful because one inevitably notices anomalies which
   require investigation when entering the data. My strategy is to take photos
   and a limited number of notes or audio files, and therefore maximise
   mapping time. This is all based on FHRS having all the other relevant data,
   which doesn't work everywhere.

   In summary using FHRS data enables a fairly targeted approach to mapping
   town centres. It greatly helps in assembling address data in such places
   and, of course, adds to the detail. For the mapper it's quite rewarding
   because one can quickly see the impact. Although shops can change a lot,
   having the much less ephemeral address data ensures this is not a Red Queen
   ('running to stay still') task.


On 13 September 2016 at 09:25, Ed Loach <edloach at gmail.com> wrote:

> Paul commented on John's suggestion:
> > Speed limits would be a good one, although impossible to armchair-map
> unless you know
> > something I don't. Also, would it stem the tide of useless speed limit
> notes from Navmii GPS users?
> I can't guarantee it would stem the tide of Navmii speed limit notes, but
> I added lots of speed limits locally when Skobbler were creating MapDust
> notes and it seemed to stem that tide.
> I like Robert's fhrs suggestion - I keep meaning to cross check what is
> and isn't mapped against the fhrs list but haven’t got around to it. Making
> it a project might spur me to do so.
> Ed
> _______________________________________________
> Talk-GB mailing list
> Talk-GB at openstreetmap.org
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