I mentioned in my previous post about why it’s great to meet up with other mappers. One thing that someone suggested I write a diary about is the method I found to be notified about map-worthy changes to one’s local area. It turns out that not everyone has heard of the London Gazette, its role in local law and administrative changes in the UK, and the online services it offers to help discover the changes.

So here’s the Wikipedia page for the Gazette And here’s the website

The core of the publication is the notices. The rules of the road network for residential and even some of the more major roads in an area (pretty much everything that doesn’t constitute the trunk road network) are delegated to local authorities, and the ritual incantation they have to go through to change those rules is to publish notices in the local press and in the London (or Edinburgh or Belfast) Gazette.

In the navigation bar at the top of the page is a Notices menu, which will list all the most recent notices in the UK.

There are filters on the left hand side of this page where you can search for and filter the list to the particular notice type and area you’re interested in. For my local area, for things I might want to add to OSM, I’ve found that the following customisations work best:

• restricting the list to Notice Code 1501

• filtering the location by Local Authority from the drop-down box (in my case, the London Borough of Ealing)

• Hitting the “Update results” button and then changing the sort order to “Latest”.

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I attended my second OpenStreetMap London social today. They happen approximately once every two months, but it’s been a year since my first one. It’s daunting, going to a pub in central London to meet a group of strangers, especially if you’re not the most outgoing person and your expectations are that they won’t be either. So I just wanted to recommend it. When you have a niche interest such as mapping the world for no particular return other than the vague idea that this stuff is really important and will change the world, it’s great to meet a few other people who feel the same way. Whether it consumes all your free time, or is just something you spend 15 minutes doing when you visit a new place, it’s brilliant to get perspectives from other mappers, to hear what motivates others, to see what they are doing with the data you contribute, and get some tips on things you might not have heard about. I can’t remember where I heard about the London meetup, but reminders are usually posted to the talk-gb mailing list, to the weeklyOSM newsletter, and to the OSMCal website, so do check those places out for updates.

History

I’ve been contributing to OSM for years now in the faith that the use cases for open geospatial data will grow over time. I’m proud of how complete my local area is, and slightly embarrassed at the thought of others seeing how many nodes and ways have my username against their history! I’m aware that OSM data is appearing in more places to the point that every time I see a map or some detailed analysis of a local area, I’m looking for the OSM reference. This has included in the past couple of years:

• Path surface and quality stats from Strava of recommended bike routes
• The live map on a British Airways flight I was on.
• a train route map

I also think the potential for customised renderings of maps is amazing, including some of my favourites:

• Cyclosm
• The OpenStreetMap Transport Map layer
• OpenRailwayMap, particularly the maximum speed rendering, which is nice for visualising the available routes to long distance destinations

Contributing is a never ending task though. It can vary from the high-level detail like landuse to the intricate detail like business opening times and whether a location is completely wheelchair accessible. Plus aerial imagery gets better over time, meaning there’s always scope for revisiting stuff you’ve already mapped to improve it. I’ve always been curious how the data could be reused, (and the WeeklyOSM newsletter is a great place to find new examples) and have started looking at online tutorials for QGIS. I’ve not done any formal training in GIS though.

Ideas

I’m quite interested in the use of sub/urban space, and so a couple of ideas I’d like to try include:

• calculating the length of protected/unprotected cycle lanes within a polygon (eg a London borough) as an absolute value and as a proportion of total road network
• calculating the amount of green space within a polygon (eg within a set of council wards) as an absolute value and proportion of total space

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