[Tagging] lanes - is "parking allowed" a parking lane?

[Minh Nguyen]

Vào lúc 06:17 2020-11-19, Tobias Zwick đã viết:
> Hello all
> 
> First of all, in the past, we have explored many edge cases for the 
> lanes-tag in various discussions and I am happy that for the most part, 
> it seems to be quite well defined by now. However, there is one edge 
> case which is not uncommon at all but still unclear or awkward to tag. 
> Look at this:
> 
> https://westnordost.de/misc/2or1lanes.jpg
> 
> It is a residential road marked clearly for 2 lanes, so it seems obvious 
> to tag it with lanes=2. But on the other hand, you'll notice that there 
> are parking cars on the right side that effectively render the right 
> lane unusable. These parking cars would (currently) be tagged I believe as
> 
> parking:lane:right=parallel
> parking:lane:right:parallel=on_street
> 
> And the wiki states
> 
>  > And the following lanes should be excluded:
>  > [...] Parking lanes [...]
> 
> So here is an ambiguity in the documentation. On the one hand, if the 
> road has marked lanes, the number of marked lanes should be tagged, on 
> the other hand, there are these kind of "parking lanes" which do not 
> have their own space marked as a parking lane but simply absorb the 
> space assigned to normal car traffic. In OSM tagging, these are also 
> "parking:lane"s as far as I know.
> 
> We need to dissolve this ambiguity by defining a way how to distinguish 
> between these two cases:
> 
> https://westnordost.de/misc/parallel_parking_lane.png
> (1) a dedicated parallel parking lane. This lane should not count as a 
> lane in the lanes-tag.
> (2) (parallel) parking is allowed (and used). This should be irrelevant 
> for the lane count.
> 
> My suggestion would be
> (1) parking:lane:*:parallel = lane
> (2) parking:lane:*:parallel = on_street
> 
> Maybe especially those who recently involved themselves with parking 
> lane tagging out and about and its documentation could also state their 
> point of view here. According to the wiki edit history, looks like at 
> least Mateusz Konieczny, Supaplex030 and Minh Nguyễn were active.
> What do you think?
> 
> There is also at least one data consumer I know about that is using 
> parking lane information and displays it visually,
> https://github.com/dabreegster/abstreet it would be good to know how 
> they interpret and visualize the data.

I'm not intimately familiar with the highway engineering standards and 
driving rules in Vienna Convention countries, but I wonder if case (2) 
is (literally) an edge case where we can tag it as a parking lane but 
not count it separately in lanes=*. After all, the roadway doesn't have 
any purpose-built infrastructure for parking, even if that's what people 
are doing.

For high-resolution renderers, maybe we need some variation on 
lane_markings=* to indicate that the parking lane specifically is 
unmarked. Or maybe a way to explicitly indicate that two lanes overlap. 
There are other cases of overlapping lanes, like turning movements that 
overlap with bike lanes [1] and often require turning vehicles to sneak 
around vehicles going straight. [2]

[1] 
https://nacto.org/publication/urban-bikeway-design-guide/intersection-treatments/combined-bike-laneturn-lane/
[2] 
https://www.latimes.com/archives/la-xpm-2003-may-27-me-wheel27-story.html "You 
can drive side by side for a mile in the same lane, as long as it’s 
large enough."

-- 
minh at nguyen.cincinnati.oh.us