[Openstreetmap] thoughts on node types, link types

[Simon Hewison]

It appears to me, as a complete newbie to openstreetmap, but someone who 
has in the past written route planning software, that it would make 
sense if the following ideas could be included in the editor and schema.

This is primarily to do with using the data for a route planning task, 
rather than just a pretty looking map.

Each node could have a node type, which would be one of a number of 
types, starting with
	nothing special
	junction
	junction with traffic lights
	mini roundabout
	mini roundabout with traffic lights
	railway level crossing
	(anything more complicated, such as a motorway junction or 
grade-separated junction may need to be represented with multiple nodes)
This sort of information makes written or spoken driving directions far 
more sensible ("at the traffic lights, turn left onto...")

link types are just as important, as it makes for useful speed estimates 
(though some of these are not really relevant in road journey planning)
	footpath
	bridleway
	cycle track
	unpaved single track road
	single track road
	residential street
	two track road without lane markings (eg wide country lane)
	street with lane markings
	three lane road (shared overtaking)
	dual carriageway
	motorway
	tramway
	preserved railway
	single track railway
	dual track railway
	airport paved runway
	airport grass runway
	airport paved taxiway
	airport grass taxiway
	ferry route

The link type could be used to render a more human-friendly map (for 
instance, using UK common practice, blue for motorway, black for 
railways, dashed line for footpath), and the link type can also denote 
the width of the line to draw by default.

Useful thought: by looking at the GPX GPS track logs, if you're 
attempting to auto-convert a track log to nodes and a link, the speed 
between points on the track log could be used to define speed, and from 
it, guess at the type of road. Direction of the track is relevant here, 
as it can be used to denote one-way streets, dual carriageways, 
motorways, slip-roads and the like.

Also, there needs to be some way of designating one-way streets, slip 
roads and the like, which would be a property of the link.

--
Simon Hewison