[OSM-talk] OSM is a right mess

[Shaun McDonald]

> On 3 Jun 2015, at 07:00, Maarten Deen <mdeen at xs4all.nl> wrote:
> 
> On 2015-06-03 02:04, pmailkeey . wrote:
>> iD shows oneway=unknown if it's not set. If it's unknown, iD should
>> not show oneway at all.
> 
> I agree.
> 
>> In OSM if oneway=no then it's not oneway and the oneway tag should not
>> appear at all.
> 
> Here I don't agree.
> 
>> The only time oneway should appear is in the case of oneway=yes - and
>> the '=yes' is superfluous.
> 
> Some roads are implied oneway. E.g. junction=roundabout and highway=motorway both imply that the road is one-way only. If for some reason the object in case is not oneway, a oneway=no tag is very much needed.
> 
> I agree that in every case where oneway=yes is not implied, oneway=no is superfluous (in a network design way), but that does not make oneway=no superfluous.
> 

There are some cases where oneway=no is useful. For example an area where there is lots of one way streets and only a few that are two way, adding the oneway=no confirms that the data is correct rather than the oneway=yes being missing. Similarly where a street was oneway previously and has recently been made two way, this makes it explicit that it is now two way in addition to whatever changeset note there may be.

Shaun