I’m undertaking a bit of a project in Burnie, a city in the state of Tasmania in Australia, and thought that I should leave a more public note about what I’m doing and the reasoning behind it. Don’t expect anything particularly entertaining from this entry. The short version: a recent import of official suburb boundary data can be used to accurately offset aerial imagery, which can in turn be used to consistently align existing mapped items across the city.

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While there are other mappers in the area, and I was most active in OSM mapping several years back, I’m responsible for a decent amount of data in the Burnie area. My process was pretty straightforward: drive to a new area, survey on foot, record GPS traces as I went. Back home I would upload the address data and anything else that needed updating and trace buildings from imagery. The best-quality imagery at the time was Bing, which was fairly average resolution and not always well-aligned, so I’d align the map to my GPS traces or publicly uploaded ones, depending on subjective recording quality. While this was in good faith, it meant that each little area I’d surveyed tended to have slightly different offsets, with no way for me to tell if any were correct. It’s minor, but many of the buildings I traced are also poorly outlined, though the older imagery probably limited how well I could do at the time.

Having resumed OSM mapping recently (after moving house - what better motivation than having a new neighbourhood to explore?) nobody had done much to improve this issue. Not surprising; it’s not the most populated area, things were good enough for routing purposes, and there was plenty that still wasn’t mapped at all. But it bothered me, and I noticed a new feature that made it much easier to resolve.

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Most of the addressing I’ve been doing recently has been straightforward - particularly if I happen to be doing it on the refuse collection day, since the council bins here have clear addresses on them.

Other days, you come across things like this:

(For the record, my undersanding is that the block starts on the ‘right’ at 36 Alexander Street, the building directly behind the sign takes up addresses 38 and 40, and the block ends at 44 on the ‘left’. But I’m not sure enough to put it on the map.)

The big goal of OpenStreetMap and the various themed projects is to provide a free & editable map of the world, or something like that, which is great (and so is the progress). But altruism isn’t the only reason I’ve found myself continuing to edit and contribute for the last 18 months or so.

Exercise

I suppose this is dependent on how and where you’re mapping. WIth the streets and major items filled out in my local area, I’ve moved on to the smaller things like addresses and sidewalks and even benches and picnic tables. That sort of stuff can’t really be done at typical driving speed, and it’s a lot more relaxing to just go for a stroll with a camera or notepad. I don’t know if it’s made a huge difference in terms of activity, but it sure beats watching TV on the couch. And it makes for good motivation - sometimes I can’t be bothered walking around the block a few times, but who knows what might be on an unseen street! Which brings me to another benefit…

Exploration & Awareness

Generally if I went somewhere in the past I wouldn’t dawdle - the journey was just time to kill until I got to the destination. Now though, even when I’m not directly mapping I’m more likely to take a different route, or see what’s down that side-street I’ve driven past hundreds of times but never actually needed to traverse, or pull over and take a look at the view instead of glancing out the car window. And though I’m still happy to let my mind wander on a good relaxing walk, I generally pay more attention to my surroundings, whether it’s an unsigned shortcut to the next street, or smaller stuff like “that’s a lovely garden” or “this would make a great photo”. Even on a larger scale, it’s a good excuse to go for a trip to a neighbouring town or park - not something particularly unusual, perhaps, but at least something I find myself doing more. And even if I get a little carried away or too far off the beaten track, it’s less of a problem, thanks to…

Knowledge

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I’m not exactly why I did it at the time, but this day last year I saved a screenshot of my town in OSM. Today seems a good opportunity to see what difference a year has made - at least, in my little corner of the world.

Here’s the old one (2013-09-20) (full-size):

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