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Road Traffic Map Based SystemsMost people are familiar with Google Maps: we started to use it to understand how to show SEQ traffic information. Google overlay transparent PNG images that contains the traffic information over the existing map. It is possible to do this with any images that the web developer wishes.
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We have started developing an application to render transparent images with roads highlighted. The road data was selected from openstreetmap.com, an open source alternative to Google Maps.
Brisbane displayed in openstreetmap.com
These images must handle muliple zooms and be split into 256 pixel tiles. Another issue arises when the user zooms out: opposing directions on the same road will be rendered on top of each other: calculations had to be done to separate them when zoomed out.
Brisbane displayed in Google Maps
The data were provided by the Department of Main Roads: these are used to produce National Performance Indicators and gave us a chance to understand the underlying traffic data and which attributes are relevant. The data are presented in a spreadsheet format.
