Mapping turn lanes

[planemad]

Objective: Map missing turn lanes from satellite imagery to estimate mapping effort

Team: @planemad w/ @mapbox/india-office @lxbarth @Rub21 @Andygol @mikelmaron

Map Features:
Focus Area: Redwood City - Palo Alto 300 sq.km

Estimated features to map: unknown
Mapping speed: unknown

Available data sources

Source	Description	Quality	License
Mapbox Satellite	Imagery	High	✅
Bing Imagery	Imagery	High	✅

Tasks

Location	Description	Start	End(ETA)	Validation
Palo Alto - Redwood City	Trial run for estimates and workflow evaluation	12/10	(12/11)

JOSM Workflow

Setup

• Task Config
• Activate the following in from JOSM preferences > Map Settings
  • Map Paint Styles: Lanes and road attributes
  • Tagging Presets: lane attributes
• Filter out non road features with boundary: | leisure: | landuse: | waterway: | amenity: | natural: | building:
• Read http://wiki.openstreetmap.org/wiki/Key:turn:lanes

Mapping

• Check all motorways for turn lanes at exits and entry points
  
• Split the road into segments based on the total number of lanes for the segment
• For each road segment tag the turn lanes based on the road markings in the direction of the way. Eg. turn:lanes=left|through|right. See OSM turn:lanes
• For bi-directional segments, use turn:lanes:backward= and turn:lanes:forward= to specify turn lanes in each direction.
• Verify correct tagging using the Lane attributes style
  

Changeset Comment: Add missing turn lanes from satellite imagery https://github.com/mapbox/mapping/issues/144
Source: Bing/Mapbox

[planemad]

Lets not add turn lanes in these cases where the only turn lane is already a mapped as a separate way.

[planemad]

Road shoulders, parking lanes or cycle lanes are ignored from the lane count. Both these roads are lanes=2

[planemad]

This is the most common scenario I was seeing: A road gets an extra lane for a left turn a small distance before an intersection.

Usually its turn:lanes=left||| or turn:lanes=left|through|through|through. A plugin that easily allows splitting and add common patterns like these will easily help scale the tagging.

[planemad]

Updated Workflow

• Focus only on turnlanes along motorways. Turnlanes on low speed and low traffic roads are not that crucial during navigation.

[planemad]

Progress

• 152 turnlanes were added in 2 days by a team of 13.
• No significant turn lanes found on motorways. More turn lanes on lower speed highways.
  
  

View Edits

[planemad]

@srividyacb can you validate the turnlanes by inspecting the edits on Overpass?

[srividyacb]

@planemad

Validated turn-lanes edits by team in Palo Alto and Redwood City Area. Lane marking looks correct in the motorway and some primary roads.

• All the motorway is having lanes and turn lanes in the appropriate turning roads.
• Some of the primary roads are also tagged with lanes and turn lanes.

[lxbarth]

Done! Nice work. This was a good first run. Let's circle back on this work once we have turn lane support in OSRM.

[Rub21]

Peru-team going to start working on this task from today on. http://tasks.openstreetmap.us/project/17

cc. @mapbox/peru-office

[planemad]

Overpass Query to review turn:lanes http://overpass-turbo.eu/s/dYa

[dannykath]

I have a doubt respecting to this way
https://www.openstreetmap.org/way/7880110/history

Do I have to consider the extreme ways? and
What would be the adequate tagging?

cc @mapbox/team-data

[dannykath]

thank for your help @samely !

[samely]

Tags are:
lanes=5
lanes:backward=2
lanes:forward=3
turn:lanes:forward=through|right|
vehicle:lanes=no|yes|yes|yes|no
bicycle:lanes:backward=no|designated
bicycle:lanes:forward=no|no|designated

So:

[Rub21]

@planemad
I've Added turn:lanes,turn:lanes:backward,turn:lanes:forward http://overpass-turbo.eu/s/dYs , but right now https://www.mapbox.com/osm-query/# does not working to get the stats and numbers. I will try it later.

[Andygol]

@dannykath @samely
for now adding of a cycle lane marking is optionally ignored

and maybe full tagging for the segment before intersection looks like

bicycle:lanes:backward=no|designated
bicycle:lanes:forward=no|no|designated
change:lanes:backward=no|no
change:lanes:forward=no|no|no
cycleway=lane
highway=primary
lanes:backward=2
lanes:forward=3
lanes=5
…
placement:forward=left_of:1
…
turn:lanes:forward=through|right|
vehicle:lanes=no|yes|yes|yes|no
width:lanes:backward=3.5|2.5
width:lanes:forward=3.5|3.5|2.5
width=15.5

[luisalanya]

cuales son las etiquetas correctas para poder terminar este tramo de la pista.

https://www.openstreetmap.org/way/206086142/history

@mapbox/team-data

[samely]

@Andygol
So, we should consider bicycle:lane as a simple lane? or not consider it?

[Andygol]

@samely
Just omit cycle lane

for above mentioned road amount of lanes=3 + lanes:forward=2 and lanes:backward=1

UPD
Look here - #144 (comment)

[samely]

@Andygol Thanks!

[ediyes]

hey @Andygol
In this case, the cycle lane is in the middle, not considered lane?

[Andygol]

@ediyes

In this case, we assume that there are 3 lanes

[ediyes]

Good 👍 @Andygol thanks

[Andygol]

@lxbarth @maning @planemad
HOV (High-occupancy vehicle lane) - http://wiki.openstreetmap.org/wiki/Key:hov

WikiOSM says that:

lane: Deprecated and nonstandard. If seen on a way, this value should be removed; instead, hov:lanes=* is the preferred tagging for HOV access restrictions per lane.

What are our next action in this case? The same as we are doing with cycle lane - ignore it?

https://www.openstreetmap.org/#map=20/38.04764317729191/-122.53252378280881

[Andygol]

@luisalanya

[Andygol]

@mapbox/team-data

You can get a link from current viewpoint in JOSM by pressing Ctrl+J or ⌘+J
or
Menu View → Jump To Position

[calfarome]

@Andygol , @planemad
In this case, the middle lane should be considered or ignored?
https://www.openstreetmap.org/node/65616303/history

[Andygol]

@calfarome
☝️ In that case we ignore middle lane and consider overall amount of lanes as 4

[dannykath]

@Andygol , how many lanes should be considered in this case?
https://www.openstreetmap.org/way/9677374/history

[Andygol]

@dannykath
if we move little, left to the first point of way/9677374, we can see arrows indicating about lanes merging to the left. Previous way have lanes=2 so after merging left only one lane. We should mark next way with lanes=1 tag

[dannykath]

thanks @Andygol !

[abel801]

@Andygol Is it good to tag this as:
turn:lanes=none|none|none|slight_right

[Andygol]

@mapbox/team-data

Case when we use slight_left/…_right, merge_to_left/…righ or left …right tagging

---

as @ediyes received claim about wrong left/right turn marking we need to clarify situation when we use turn:lanes=slight_left/turn:lanes=slight_right instead of turn:lanes=left/turn:lanes=right

;tldr

• if we change movement direction -> turn:lanes=right, turn:lanes=left.
• in case when direction of movement is unchanged and
  • road became wider -> turn:lanes=slight_right, turn:lanes=slight_left
  • road became narrower -> turn:lanes=merge_to_left, merge_to_right

---

Here is comprehensive MANUAL ON UNIFORM TRAFFIC CONTROL DEVICES http://regulations.delaware.gov/register/july2011/final/mutcd/index.html (See also https://en.wikisource.org/wiki/Page:UK_Traffic_Signs_Manual_-_Chapter_5_Road_Markings._2003_(Sixth_Impression_2009).pdf/1)

Full description about road markings is in the Section 3 - http://regulations.delaware.gov/register/july2011/final/mutcd/Part3.html

---

• At this images represented using of turn:lanes=merge_to_left marking.

  We mark specific lane, with diagonal arrows, at its end to give direction to move to the left lane. The main direction of movement remains unchanged

  

  

• We use turn:lanes=slight_right (…_left) tagging in case when roads get extra lane from the right(left) side to prepare for the next maneuver to the right(left) side direction, like exit from freeway.

  Rightmost extra lane before the solid white line should be marked as turn:lanes=||||slight_right

  

• We use turn:lanes=left|right tagging when driver have to change their movement direction at an intersection

  

[Andygol]

@abel801
Nope - #144 (comment)

Here is turn:lanes=|||right

[abel801]

Thanks @Andygol I will read this

[Rub21]

@Andygol :
what about the turn:lanes=merge_to_left? ( merge_to_right, merge_to_left)

It is quiet same as turn:lanes=slight_left http://wiki.openstreetmap.org/wiki/Key:turn.

what should be better? turn:lanes=merge_to_left or turn:lanes=slight_left

[Andygol]

@Rub21
Great remark 👍

I completely overlooked that we have two options when the road gets wider and when the road becomes narrower 😨

Therefore it is necessary to clarify that

• when the road becomes narrower, we denote it as turn:lanes=merge_to_*
• when the road becomes wider, we denote it as turn:lanes=slight_*

---

UPD #144 (comment) updated according to this ☝️ remark

[luisalanya]

@Andygol

you need to add additional ways to turn right

[Andygol]

[planemad]

@mapbox/team-data lets limit the scope of the task to only turn lanes on highways tagged motorway or trunk and junctions with on motorway or trunk. Ignore turn lanes on other roads.

Important

• Only focus on turn lanes indicated by solid white lines. Read the full turn lanes wiki documentation
• The only tags to use are turn:lanes turn:lanes:forward turn:lanes:backward

[RichRico]

@Andygol

This road has 12 lanes, but when I tag it I can see just 8 lanes
https://www.openstreetmap.org/way/394138508/history#map=19/38.02684/-122.11385

[Andygol]

@RichRico

maybe this style limitation

Upd. This is definitely style limitation - https://josm.openstreetmap.de/wiki/Styles/Lane_and_Road_Attributes#Code

…
change_forward_1_left: yes; change_forward_1_right: yes;
change_forward_2_left: yes; change_forward_2_right: yes;
change_forward_3_left: yes; change_forward_3_right: yes;
change_forward_4_left: yes; change_forward_4_right: yes;
change_forward_5_left: yes; change_forward_5_right: yes;
change_forward_6_left: yes; change_forward_6_right: yes;
change_forward_7_left: yes; change_forward_7_right: yes;
change_forward_8_left: yes; change_forward_8_right: yes;
…

[jothirnadh]

While validating blocks I came across these bidirectional ways.

Are we concentrating on mapping these ways as well or can we skip them?
@Andygol @planemad

[abhisheksaikia]

The symbol pointed in the junction above represents merge_to_left. Since our priority is to strictly map turn lanes and not merge lane information right now, should we continue adding it when we move forward with the task? Or should we ignore it(along with merge_to_right) going forward for now?

Also it is found that the turn lanes wiki is very ambiguous about the differentiation between slight_left/left and slight_right/right tags. So we have decided to add turn:lanes=left/right instead of turn:lanes=slight_* to make the process simplified.

/cc @Rub21 @Andygol @planemad @lxbarth

[Andygol]

@abhisheksaikia

In ☝️ above mentioned case left turn is prohibited you can move only in straight forward direction. Just ignore merge_to_left arrow

🔽 Allowed movement direction 🔽

[abhisheksaikia]

The next task for turn lanes in the Menlo Park and Palo Alto area is published: http://tasks.openstreetmap.us/project/18. This task will include all the turn lanes from tertiary and above.

Before jumping onto this task, let us continue adding turn lanes to the previous task in SF and complete it: http://tasks.openstreetmap.us/project/17.

cc @mapbox/team-data

[abhisheksaikia]

Initial task: http://tasks.openstreetmap.us/project/17 completed and validated. We are closing this ticket and tracking all further progress in #153

cc @mapbox/team-data