Note: This is currently a proposed relation, the currently agreed on method for achieving this is by splitting the way.
Tags for a Way are used given for a complete way. If a tag references only a certain part of a way, you have to cut the way into two or three ways.
A Segmented Tag references a certain part of a way, a segment. (This is not the same as a Segment of the OSM API before version 0.5!)
The tags field holds key/value pairs for all tags which shall be applied to the part of the way given by the three members of the relationship: a way and two nodes of this way specifying the way segment. The tag keys type and direction are attributes of the relationship, all other tags are attributes of the way segment.
|direction||both, positive, negative||the following tags are valid for this direction (default: both)|
The following three members are specifying the way segment:
|Way or Node||Role||Recurrence?||Discussion|
|from||one||start node of the way segment (node has to be part of the way)|
|to||one||end node of the way segment (node has to be part of the way)|
Ways with a tag having different values for each driving direction: the maximum speed can be different for different segments of a way and can be different for each driving direction. Instead of cutting the way each time the maximum speed for one direction changes, specify a segment and, if necessary, a direction with the appropriate maxspeed tag.