[Tagging] Carriageway divider

[Tobias Knerr]

On 20.08.2012 16:53, Pieren wrote:
> The proposal with "divider=solid_line" has a disadvantage : the
> meaning of a solid line differs in countries/continents. It should be
> better tagged with "divider=no_u_turn" or "no_crossing" or whatever
> you like describing the restriction, not the painted line itself.

I disagree for two reasons.

One is that the actual road marking pattern and the derived traffic
rules are *both* interesting for applications, depending on use case.
For example, if your application is doing lane visualization, the actual
pattern could be used:
http://www.pocketgpsworld.com/reviews/garmin-nuvi-765/lane_assist1.jpg

So translation will need to happen anyway, the difference is just the
direction. And while the translation form marking to meaning is always
unambiguous (if you know the laws of the place), the other direction
isn't necessarily.

The other reason is that lines have multiple meanings (a solid line
might have implications for overtaking, u-turns, other turns, etc., and
there might be exceptions for emergency vehicles, obstructed lanes and
so on). So you might need multiple tags to map the effect of a single
line, and mappers might forget or not even know about some of them.

The line style, on the other hand, is easy to identify on the ground and
tag.

So I think that mapping divider based on pattern type is a better choice
than mapping them based on their legal effects.

Tobias