Keep Right/130 floating islands

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Message: This way is not connected to the rest of the map

Finds roads, that are not connected to other roads.

Tags that are checked:

This ways are only used for network and are not reported as unconnected if they are not.

Continent World Africa America-Canada America-Central America-South America-US Asia Australia-Oceania Europe
20150907 1,623,587 230,835 98,243 74,696 97,203 180,524 551,723 40,185 350,165
20141230 1,739,708 303,810 96,002 93,344 103,409 160,362 592,813 37,762 352,204
20140423 1,600,553 84,855 127,667 84,621 97,722 137,448 712,734 32,743 322,761
20131003 1,545,793 70,332 132,426 71,854 97,640 126,827 715,094 31,549 300,069
20130710 1,566,153 63,541 131,223 67,567 94,777 127,586 756,815 26,586 298,056
20130116 1,448,568 54,370 164,645 68,534 108,593 116,654 619,212 29,491 287,067
20121112 1,267,839 45,001 164,317 68,029 113,225 137,630 415,625 32,696 291,314
20121015 1,288,223 47,315 163,907 68,736 113,714 156,820 403,691 35,083 298,955
20120926 1,350,783 47,469 163,958 68,060 116,854 173,638 437,479 38,273 305,050
20120917 1,819,948 93,144 163,432 70,184 116,113 181,437 661,932 221,983 311,687
20120913 1,819,759 93,096 163,498 70,391 115,985 181,749 660,438 222,038 312,528

Author's comment:

  • thesis: any point in the whole map should be connected to any other node. In other words: from any point in the whole map one should be able to reach any one of well known points that have to be defined (for performance reasons: at least one point on every continent). This check includes even small islands because ferries are considered to be highways. So it is not necessary to define starting points on every island.
  • include all ways tagged as highway=* (but exclude highway=emergency_access_point and highway=construction as they are left unconnected intentionally), route=ferry or railway=platform (a platform may connect roads in rare cases), don't forget about parking spaces as they can connect roads in some cases. include furthermore ways that are part of a route=ferry relation even though the ways themselves are not tagged as ferry.

"Floating islands" explanation and issues

Any highways drawn on the map should be accessible by car starting anywhere in the world. Ferries and highways (even railway platforms) are included in "floating islands" check, so almost any island in the sea should be reachable starting from the mainland.

The check works like this: pick some starting highways somewhere around the globe (There are about 100 points picked). Then find all nodes that belong to these ways. Now find other ways that are connected to these nodes. Now find again nodes that are connected to these ways, and so on. The check starts somewhere and travels all roads until there are no more. In the end each highway that has not been visited is marked as a "floating island".

One of the side effects of that is if your country/city/island/... is not connected with the rest of the world, you will get LOTS of such errors apparently without cause. When you fix your connections to the world, most of them will go away (on next update, see above). If you have trouble finding what causes the errors and they don't disappear in a week (maybe somebody fixed it recently, but the map was not updated yet) look on the keepright.at for instructions of contacting the map owner.