[Openstreetmap-dev] More on GPX schema

nick at hogweed.org nick at hogweed.org
Wed Sep 21 16:16:25 BST 2005

Been looking at the official GPX schema, in combination with what 
OpenStreetMap does so far with GPX files. Given OpenStreetMap treats each 
track segment as a separate <trk> element in GPX, there appears to be no need 
for GPX extensions.

Currently, the OpenStreetMap GPX format places the track ID in the <name> tag. 
However, the GPX schema indicates a <number> tag for the <trk> element. 
Therefore, would it be a good idea to place the ID in the <number> tag, and 
the name of the segment (e.g. Lodge Road) in the <name> tag? e.g.

<name>Lodge Road</name>

The GPX schema also includes a <desc> (user description) tag. If we're using 
Steve's suggestion for representing keys and values as a semicolon separated 
list, they could go in the <desc> tag. The name should perhaps be separate 
from the key/value list, as a name is a pretty fundamental feature of every 


<name>Lodge Road</name>
<desc>foot=yes; horse=yes; car=yes; class=secondary</desc>

Secondly (I think this is happening anyway...) I believe it's important that 
trksegs contain multiple nodes (points), rather than just two; for instance 
in the above example, if Lodge Road contained 10 nodes and 9 segments of two 
nodes (rather than 10 nodes and one segment of 10 nodes), each of the 9 
segments would need the meta-info (name, keys and values) attached to it, 
wasting space in the GPX file and slowing down upload and download.


More information about the dev mailing list