Throughout this post I use the term major road to refer to the five uppermost highway classes in OpenStreetMap: highway = (1) motorway, (2) trunk, (3) primary, (4) secondary and (5) tertiary, as described on the international wiki and the Australian tagging guidelines. So what do all those tags show? To find out, I collated the highway surface data from OpenStreetMap to explore the patterns of sealed and unsealed major roads across Australia. That’s an amazing accomplishment by the mapping community, and a great resource for anyone who drives a truck or tows a caravan around the country and who wants to stick to the tarmac and avoid the dirt. Nevertheless, we’ve reached the stage whereby it’s possible to say that, with localised exceptions, nearly all major roads across Australia now have a surface tag on OSM. Source: OpenStreetMap, June 2021.Īt the “end” of the process, when I looked back over the areas I’d worked on earlier, more new roads had been added to the map, and many of those don’t have surface tags either. Tertiary roads are not shown for clarity.
Virtually all major roads in Australia now have surface tags in OSM.Ĭolors show road hierarchy levels: black=motorway red=trunk blue=primary gold=secondary. Having said that, two huge gaps defeated me: in Perth and Melbourne, but both are in urban areas and nearly all of the untagged roads in those areas will be paved. the road was under dense trees or wasn’t visible on available imagery).
Gradually, only a few dozen roads remained without surface tags in most states usually where I couldn’t determine the surface type (e.g. Like thousands of mappers before me, I pottered away and filled some gaps.
Early this year, after editing roads near my home, I looked further afield and realised that, if some gaps on OpenStreetMap (OSM) were filled, virtually all major roads in Australia could soon have a surface tag to show whether they were paved or unpaved.