[OSM-talk] Highway tags and other junk

guy at graviles-reynolds.org guy at graviles-reynolds.org
Fri Dec 15 04:28:17 GMT 2006


Having read through your email and looked at the tracktype proposal, it occurs 
to me that you are possibly thinking about this too much and form an even more 
local point of view than even being UK centric.

Starting from the top, the road designations Trunk, Primary, Secondary, 
Tertiary, Unclassified and Track ( I am ignoring motorways as a special case 
and residential as these are ineffect unclassified roads with pre-applied 
residential abbuters) are political/usage definitions which once described the 
way roads were used but are now used for social engineering, in order to 
enforce preference to one road over another. One only has to look at the road 
numbering history around Baldock, to see this. It is this enforced preference 
information that has to be mapped in the first instance.

These designations however bear no relationship to the physical nature of the 
roads, they are there to enforce preference, arguing road designations on 
grounds of their physical nature is verging on rediculous, shows localised 
thinking in extremis and goes against what people are trying to achieve with 
regards to traffic management by means of these designations. 

Travelling around the globe, I have driven on many roads which have been 
designated as 'Trunk Roads' but which ranged from 8 lane highways with hard 
shoulders, through dual carriage ways, single lane roads with passing points 
and on down to a line of poles marking a route across a desert. In the last 
instance getting out the vehicle to measure the width of the road to ensure it 
was of a certain type would have been a bit pointless (>1000km?). 

The important thing was that these were all trunk roads, thus need recorded 
same fashion and be given the same basic rendering on a map. However but this 
needs then to be augmented by additional keys describing the width, surface 
type, verges, hedges, fences etc and minor changes to the rendering. Whilst 
this leads to a single highway having, a large number of additional property 
tags which have to be labouriously keyed in for each way, it gives the freedom 
to describe the exact nature of the highway. Whereas grouping the properties as 
you have done with tracktype restricts the variants to too few, which are 
potentially only capable of describing the tracks in your locality in the UK, 
let alone all the highways around the world.  

When it comes to measuring width, if there is a very tight restriction then 
will often be signs giving the width, otherwise from my point of view giving 
the number of lanes is sufficient and this can be done without the need to 
leave the vehicle. 

Guy

 








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