data consistency checks for OSMnon-closed areas
By convention ways tagged with special combinations of key and value pairs are considered to be areas and are drawn as such in the map. Therefore it is necessary that they form closed loops. Non-closed areas are invisible in the map! The standard.xml file is used to determine which key-value-combinations are drawn as areas; any instance of these has to be closed-loop.
dead-ended one-ways
Streets tagged as one-way must not be dead-ended (where should all the cars pile at the end of the road?)
almost-junctions
Streets that have (at least) one unconnected end are examined here. If such an end-node is very close to any other way an error is reported. Unconnected end-nodes should probably be connected to adjacent ways.
deprecated tags
As shown in http://wiki.openstreetmap.org/index.php/Deprecated_features some tags get replaced by others as new tagging conventions evolve.
missing tags
Ways, nodes and relations should in most cases have at least one tag (besides created_by)
bridges or tunnels without layer
Bridges and tunnels need a layer tag as a hint for map drawing processes for achieving correct visibility of elements. THIS CHECK IS OBSOLETE.
motorways without ref
The ref-tag documents the reference (e.g. 'A 10') for motorways. These are mandatory as they are very important information
places of worship without religion
Churches, mosques and synagogues etc. need an extra religion tag giving info about the religion
point of interest without name
The name tag should be specified for every point of interest as its content gets rendered in the map next to the POI symbol
ways without nodes
Ways that don't consist of at least two nodes don't make much sense as they won't get rendered. Question is: How can one delete a way without nodes?
ways with name tag, without frequently used tag
Ways tagged with a name-tag are supposed to be highways, buildings, amenities etc. So they need more tags defining the type of object. Objects having a name but none of frequently used type tags are reported in this check
railway crossings without tag
(Level)-Crossings of railways and highways should have a common node as junction that is tagged with 'railway=level_crossing' if it is a crossing where larger vehicles can cross or with 'railway=crossing' if it is a crossing just for pedestrians
wrongly used railway crossing tag
Ways that take part in level-crossings of railways and highways have to be on the same layer and should in the normal case be not tagged as bridge or tunnel
fixme-tagged items
Nodes, ways or relations that are tagged with FIXME should be reviewed...
relations without type
Find any relation that has no type tag, wich is mandatory for relations.
intersections without junctions
Streets that graphically intersect need a common node that represents the crossing. The only exception are intersections on different layers (eg. bridges or tunnels).
overlapping ways
Segments of ways that lie on top of each other (the same nodes connected by different ways in the same order) are a problem for routing software. They happen accidently and are hard to find.
loopings
Any way that contains any single node more than twice is considered an error. Any way may contain just one node twice. If more than one node is found twice it is considered an error.
misspelled tags
Tags that are used very seldom and almost look like very common tags (only one character difference) are reported as a warning.
Mini Roundabouts
Mini Roundabout direction is marked correct for driving on left/right side of road