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

I thought I’d record my progress here in a few blogposts, including:

• useful datasets I find outside of OpenStreetMap
• the method I work out for answering these questions
• any difficulties I find

I’d welcome any suggestions for:

• better ways I could be doing things
• advice on how to solve the problems I encounter
• links to other peoples’ favourite blogs/youtube videos etc for learning this stuff

Starting point

I need shapefiles for the London administrative boundaries (boroughs and wards). The Office for National Statistics produces loads of useful datasets in their Open Geography Portal under the Boundaries menu (I can’t hyperlink this group, annoyingly!) But those datasets are nationwide, and I’m particularly interested in London boundaries so I tried the London data portal. This page has a zip file including borough boundaries and ward boundaries.

I’ll follow up with another blog post with the OSM data processing I do.