[OSM-talk] definition of the main highway-tag

[Lester Caine]

John Smith wrote:
> 
> 
> --- On Tue, 4/8/09, Richard Mann <richard.mann.westoxford at googlemail.com> wrote:
> 
>> The potential problem for renderers is that
>> there's a lot less space to render things in urban
>> areas, so they benefit if lower-order roads are
>> distinguishable between urban areas (so they can be narrowed
>> or suppressed), and rural areas (so they can be used to help
>> fill up the space). Abutters seems to offer one way of
>> indicating to the renderer that it's within the urban
>> area without creating yet another highway tag.
> 
> The problem with that is it would require abutters tags and/or be ambiguous as to what class of highway it is, I also don't think it's a very good idea using one class of highway for 2 very different purposes.
> 
> Some people are using highway=unclassified to mean a wider than residential road which seems to contradict the wiki reference:
> 
> "No administrative classification. Unclassified roads typically form the lowest form of the interconnecting grid network."
> 
> This means to me to mean lower than residential, but the opposite has been used and some take it as higher than residential.

highway tag identifies a linear feature that can be navigated along ... what 
seems to have been lost is the distinctions that are applied to train and 
water traffic, so while we have waterway and railway, we do not have 'footway'

waterways have towpaths which are footways and so do some railways although 
those WOULD normally be marked with separate routes and so perhaps should 
towpaths. But the point I'm trying to make is that route which are essentially 
vehicle free are not easily identified currently.

If these routes are stripped off from the 'highway' network, and route that 
are essentially vehicular are identified by 'highway', then we tidy up the 
definition of highway, 'cycleway' and 'bridleway' might complete this picture?

We then come back to the relative 'levels' of highway tag, and these ARE 
fairly well formed for the major road classifications, motorway, trunk, 
primary and secondary form the major vehicle routing system, and I will not go 
into rant mode here about 20 mile per hour speed limits on primary roads 
because they are 'residential' - in that instance there is a missing bypass 
route of some sort ;)

Roads within industrial areas or housing estates, may be 'short cuts' on the 
main 'interchange' map, but unless those routes are designated primary or 
secondary, the '20 mile per hour' speed should be considered to apply as these 
are essentially areas where the vehicular use is not the primary use, and 
children playing or vehicles being unloaded takes a higher priority?

'Urban' areas should on the whole be covered by 'residential' or 'service' in 
between the 4 main vehicle route tags. Although personally I'd prefer that 
motorway service roads were not grouped with 'industrial'. 'shopping' may have 
a place for filling in the gaps in these cases, but I do not see any reason 
that 'unclassified' would be used within an urban area?

This leaves tertiary and unclassified for those roads outside urban areas and 
on the whole tertiary probably applies better leaving unclassified for roads 
such as farm tracks or routes where the vehicular usage may be questionable. 
Certainly an 'unclassified' highway should not be capable of handling a large 
lorry so routes for access to farms should be tagged 'service' perhaps where 
such access is practical, and 'track' needs to be tidied in the same context?

'living_street' is a footway with limited vehicular access as is 'pedestrian'

I think I could well make a case for a 'way' having a 'highway', 'cycleway' 
and 'footway' tag if appropriate, so American motorways that have cycle access 
would simply add a 'cycleway' tag with separate linking ways if appropriate?

-- 
Lester Caine - G8HFL
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