[OSM-talk] [Tagging] - RFC - Motorway_link implies oneway=??

[Alex Mauer]

Claudius Henrichs wrote:
> Can you tell any advantage of implying highway=motorway_link to be oneway?

It depends on what you're comparing it to.

versus implying it to be oneway=unknown, there's a reduction in the 
amount of tagging needed because less than 100% of the ways with 
highway=motorway_link need to be tagged with oneway=yes/no.  And of 
course, a routing application specifically can't use oneway=unknown 
(they have only the choice of "use the way for routing" or "don't use 
the way for routing".  So a routing application would have to make their 
own decision on which assumption to make)

versus implying it to be oneway=no, there's *probably* a reduction in 
the amount of tagging needed, because there are probably more ways with 
motorway_link that are oneway=yes than oneway=no.  In addition, for a 
routing application it increases safety.  It's a lot worse to route 
someone the wrong way up a one-way motorway_link because it was assumed 
to be two-way than it is to send someone on a longer/slower route 
because it was assumed to be one-way.