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--></style></head><body lang=EN-US link=blue vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-GB>The real easy way to understand <i>culverts</i> and <i>fords</i> for OpenStreetMap is about the layers they are on and this dictates the nodes they use.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>For a <i>ford</i> the stream/river is at the same level as the road (effectively <i>layer=0</i>) and therefore they are able to share a node.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Because a culvert (<i>layer=-1</i>) is not on the same level as the road but passes underneath so it cannot share a node with the road and therefore the culvert is attributed to the river/stream with a node either side of the road.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>With a <i>bridge</i> the road (<i>layer 1</i>) is not on the same level with the stream/river so again cannot share a node and therefore the bridge is attributed to the road with a node at each end of the bridge.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Hope this will be of help in understanding the problem.<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Sent from <a href="https://go.microsoft.com/fwlink/?LinkId=550986">Mail</a> for Windows 10</p><p class=MsoNormal><o:p> </o:p></p></div></body></html>