Reuse and Prosper

So my cycle map here on Gravitystorm isn’t likely to become the world’s one stop cycle website any time soon. I don’t have the time, and I certainly don’t have the skills, to add all the bells and whistles to attract megathousands of pagehits per day. So what’s the long term strategy?

Who knows? Not me anyway! For now, I’m going to continue to work on the cycle tiles, making them look better, showing more useful things that cyclists might be interested in – eagle-eyed observers would have noticed one of the first changes I made was to show pubs at many more zoom levels! There’s plenty of things in the pipeline in this area.

One of the main beneficiaries of the cycle map is the OpenStreetMap project itself, since it acts as a great demonstration as to the possibilities of specialist cartography – something that’s just not possible with layering more and more objects over the top of a google map. But the best way for cyclists to benefit is for their own, specialist websites to swap google for OSM. The first two websites to reuse my tiles are, and the excellent Camden Cycle Campaign website, where the OSM cycle tiles are an optional backdrop. Hopefully the coverage of the cycle data in central and north London will rapidly expand – if we can do that, I think we can persuade the CCC to use our OSM tiles as the default layer!

So if any of you reading this know of other websites that could benefit from better cycle maps, then let me know. I can already think of one mountain biking route map (like the link, Gary?) that would be ten times better if it could show nearby pubs!

7 thoughts on “Reuse and Prosper

  1. Steve Chilton

    I like the way the key works on this map. Transparency, rollover, etc. You might want to share your solution to tone overlays (at joins in cycle routes) with them!

  2. Steve Chilton

    Yeh, sorry, I realised when I had posted it that it might not make sense because of context. I meant the Camden Cycle Campaign one that is transparent and is hyperlinked.

  3. George Coulouris

    Thanks for the comment about the key/menu on our (Camden CC) map. It took quite a lot of trial-and-error to get the DOM programming right for that one.

    So Andy, what is the secret to tone overlays? (Though I doubt it will be implementable with the Google API’s polylines). One day we’ll move to an open API (OpenLayers?) but not soon.

  4. Andy

    The secret is that every semi-transparent line needs to be drawn with no transparency to a buffer before the entire lot is applied with alpha-blending to the rest of the image. It’s the only way to avoid additive transparency where they overlap. Doing this for the cycle map involved getting a new API for the rendering tool (mapnik) – each section of the map is drawn to around six different buffer images (background, lcn, rcn, ncn, overlay and a couple of others) which are finally overlaid on each other with the appropriate transparency.

    I doubt that the Google API (or anything else, for that matter) will let you stroke each line to a buffer before applying transparency in one go – almost everything will draw each line semi-transparently one line at a time, which leads to the overlap problems.

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