[Tagging] New proposal: Obligatory tagging of oneway on motorway_link

[moltonel]

On 10 September 2015 13:20:43 GMT+01:00, Joachim <noreply at freedom-x.de> wrote:
>Proposal:
>Define on the wiki page of highway=motorway_link that oneway=* must
>also be tagged for every motorway_link.

Sounds fair.

> If not tagged, the oneway=*
>status of this way is undefined.

You wont gain anything by de-defining the "oneway=no" default value. Consumers (routers, renderers, whatever) will not be swayed by a wiki page. They might look at stats and decide themselves what the absence of a oneway tag means, but a wiki proposal is never going to influence that decision.

>- For routing purposes it is recommended to not route over ways with
>undefined oneway since any assumption may be wrong and it would be
>best to correct the data.

That's a very bad idea. Routers implementing it would skip a motorway exit (and lenghten the trip greatly) because of a missing tag. I'd much rather get to the exchange, see that the router is suggesting a link i cannot take, and drive around to find a nearby link I can use. Still frustrating but less time wasted.

>- In map editors undefined oneway should be displayed as tagging error.

And *that* is the actually usefull thing to do, instead of the proposal. File a bug to the major editors and QA tools suggesting to flag motorway links without a oneway tag as an warning.

Even better: if the software has the means to do it, flag that warning for any object having tag foo but not tag bar, if 95% of foo tags in the db are accompanied by a bar tag.
-- 
Vincent Dp