Cases in point: https://www.openstreetmap.org/changeset/39930495 & https://www.openstreetmap.org/changeset/39934184
Both people on took out the ‘none’ from the “turn:lanes:backward” tag. From “none;slight_right”, to “slight_right”. Now the info for that section is completely WRONG. The ‘none’ is there to indicate that the road there is splitting into two lanes. With taking out the ‘none’ part, it indicates that there’s only one direction the lane is going.
Here we have them removing the ‘none’ from beside the ‘slight_left’ indicating there’s a new left lane starting.
Gotta just love who think everything is an error…….. ‘none’ is a VALID tag for turn lanes for crying out loud!!
Comment from PlaneMad on 11 June 2016 at 02:12
This looks like an error in how empty turn lanes were detected and I just documented it on osmlint for correction. The context for the cleanup was the occurrence of tags like turn:lanes:backward=none|none|none and similar, and checking if the turn lanes count matches the number of lanes.
One of those two checks seems to have flagged such cases in error, and it was a mistake on the mapper part to not highlight the inconsistency as it was spotted.
Is this a common pattern on only two lane roads, or does such marking appear on larger highways as well? Weighing the option to either revert all the changes or just those that match a certain tag combination.
Comment from rickmastfan67 on 11 June 2016 at 02:20
This can possibly happen on bigger roads when a new lane is being added to the highway. See my new post on the tagging list explaining how I’ve been using ways with the “none;slight_right” & “slight_left;none” tags: https://lists.openstreetmap.org/pipermail/tagging/2016-June/029342.html
Comment from escada on 11 June 2016 at 09:04
for me, both slight_left;none and none;slight_right are wrong. none can only be used on a lane by itself, when there is no arrow on the ground (or traffic sign). For your purpose I would consider something like transit:lanes
Comment from jc67 on 13 June 2016 at 11:39
without commenting the semantic of the point, I would like to say that the notation itself should be taken into account.
PlaneMad wrote : turn:lanes:backward=none|none|none
when rickmastfan67 wrote for the value itself : “none;slight_right” & “slight_left;none”.
Shouldn’t we agree on how to store the info ?
What I saw is that, in Potlach, the fields that contain a list of values with a “;” separator appear as errors/alerts.
Therefore, I would recommend agreeing on using the “|” as the standard separator… as long as it doesn’t appear as well as an error in Potlach !!
Comment from LeifRasmussen on 26 May 2019 at 21:05
“left;none” makes no sense, unless “none” is always understood as “through with no markings”.
I’ve created a proposal for a new type of from-via-to relation that would solve this problem of lane markings not matching actual lane connectivity, as well as a ton of other issues with turn:lanes.
A connectivity relation could be used at that location to state how the lanes connect that would override the “turn:lanes”, allowing that tag to only state the lane markings, not the connectivity.
If anyone has any suggestions for how to improve the proposal, please let me know!