Dave F (et al), Renderers draw roads (typically) by drawing a wide grey line on each segment, a grey circle at each node, then a narrower (say) white line on each segment, and a white circle at each node. All you see of the grey is a thin line on each side of the white line: this is the casing. The circles on each node are called caps (end-caps if they are at the end of a way, join-caps if they are at an intermediate node).
If you don't draw the circles on the nodes then you get gaps at corners. If you draw all the grey first, regardless of layer, you get gaps in the casings when one road goes over another, so it looks like they join when they don't (which happens on cyclemap). If you draw the grey in the correct layer, then you get little semi-circular arcs of grey at the end of bridges (if they are layer=1). So renderers have to do something. Different renderers have come up with different solutions, but all produce artefacts because there's a piece of data missing (which they could pre-process, sure, but there are better uses of time). It would be more effective to give them the data, and have renderers do it reasonably well consistently. What I've suggested isn't the only solution, but it's the most economical, I think. Richard _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging