[Tagging] Ferry routes, what's the correct approach?

[Philip Barnes]

On Sun, 2012-06-03 at 11:05 +0200, sabas88 wrote:
> Hi,
> I started discussing in the local list about the approach in tagging
> ferry routes.
> The wiki page [0] seems a little bit unclear, leaving two approaches:
> -normal way between harbours
> -relation like a normal road.
> 
> 
> I tried to follow the relation approach like I saw in other seas, but
> I cannot understand why routing on these ferries is so difficult.
> For instance in some cases the router suggest to change ferry in the
> middle of the sea, or suggest a route which minimises the sea
> crossing: between two harbours with a direct line, it goes through
> land till it find another route.
> 
> 
> So, my question is: it's fault of the tagging or the routing? What's
> the correct way of tagging?
> 
> 
Dover-Calais does seem to work well, you may get some ideas there.

http://map.project-osrm.org/xR

Phil