[OSM-talk] [Fwd: Re: Proliferation of path vs. footway]

David Earl david at frankieandshadow.com
Thu Aug 13 19:24:05 BST 2009


On 13/08/2009 18:20, Norbert Hoffmann wrote:
> David Earl wrote:
> 
>> So I say: keep it simple, keep it compatible. Carry on with the simple, 
>> established tags we already have, but just clarify the default use 
>> classes which apply to each highway tag, PER COUNTRY, and tag exceptions 
>> to these according to evidence on the ground. Add specific legal 
>> designations only where expert knowledge is available and different from 
>> the default interpretation.
> 
> I say: forget all defaults and store all those values in the database.
> Those only partly documented "defaults" are the cause of the discussed
> problems. The process of tagging may be as simple as it is now. Let the
> user choose which country he is in (or which country's rules are in his
> head while editing) and than the editor can add those defaults.
> 
> What we win with this method is, that the apps working with the data need
> not know anything about country borders or specific legals and changing
> some default in the WIKI will no longer invalidate data.

So what you're saying is that

- each editor and data consumer has to have its own set of national
rules and defaults rather than defining them centrally (so inevitably
they'll end up different);

- we have to massively increase the amount of data we store by saying
for every road that it is open 24 hours a day (because some aren't) and
has a 44 tonne weight limit (or whatever it is by default in your
country) except for the few cases where it isn't; all cycleways don't
permit llama pack animals (because some in Peru do) and all motorways
explicitly do or don't permit horse drawn vehicles.

- we can't type a simple tag any more, we have to go via a menu or a
form because there are so many of them. Every highway would have to
carry maybe thirty or forty tags giving use cases, and every time we
realise we are missing a use case (say we discover motorways in Ecuador
permit learner drivers to use them [please don't tell me this isn't the
case - it's only an example]) we have to add tags to every other highway
in the world to say that there learner drivers can't, otherwise we're
assuming a default.

- and that we have to update almost every way in the system already and
change every bit of software we already have

David





More information about the talk mailing list