[mkgmap-dev] special cases in restriction relations, r3178 still not perfect

Fri Apr 11 14:40:14 BST 2014

Hi Gerd,

 > Sure, the car driver always has to make sure that the route is
 > allowed, but I think we want to avoid to calculate (and show)
 > a route that is not allowed.

I think this is road sign like in row '7' here:
http://wiki.openstreetmap.org/wiki/Relation:restriction#Road_signs

Even if you convert it to '1b' with restriction=no_left_turn, the 
problem remains the same.

 > Only, for this very special case it would probably require many
 > lines of code to find out which way is correct. It already required
 > many lines to detect the special case ;-)

I haven't browse your code for restriction, but I get the feeling, that 
it is complicated :)

 > I'd prefer to change the wiki and say that this case must be avoided.

It won't be easy to define this case for a common mapper.

What condition is triggered in your code? A loop? Repeated node? Or 
maybe multiple ways fitting as via for restriction?

-- 
Best regards,
Andrzej