Mapping turn lanes in SF peninsula, DC and LA

[abhisheksaikia]

Objective: Map missing turn lanes from tertiary and up in SF peninsula, DC and LA.

Team: @mapbox/team-data

Features to map: Turn lanes (motorway, trunk, primary, secondary and tertiary) from satellite imagery

Focus Area: SF peninsula and DC

Estimated features to map: unknown

Mapping speed: unknown

Available data sources

Source	Description	Quality	License
Mapbox Satellite	Imagery	High	:white_check_mark:
Bing Imagery	Imagery	High	:white_check_mark:

Tasks

Location	Description	Start	End(ETA)	Validation
Palo Alto - Redwood City	Trial run for estimates and workflow evaluation	12/10	(12/11)	Completed
SF Peninsula	Turn lanes on motorway and trunk junctions in San Francisco Peninsula	20/01/16	5/02/2016	Completed
Turn lanes in Palo Alto - 1	Mapping turn lanes on highways tertiary and up in Palo Alto	08/02/16	09/02/16	Completed
Turn lanes in DC - 1	Mapping turn lanes on highways tertiary and up in DC	08/02/16	08/02/16	Completed
Turn lanes in SF city	Mapping turn lanes on highways tertiary and up in SF city	09/02/16	10/02/16	Completed
Turn lanes in DC	Mapping turn lanes on highways tertiary and up in DC	11/02/16	12/02/16	Completed
Turn lanes in LA	Mapping turn lanes on highways tertiary and up in LA	12/02/16	29/03/2016	Completed

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:
• Add inverse filter: highway=motorway | motorway_link | trunk| trunk_link | primary | secondary | tertiary
• 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

  Issues to keep in mind:

• For now we ignore adding cycle lane marking
• slight_left and slight_right can be ignored and instead right and left turn lane tags should be used to avoid ambiguity.
• Bi-directional lanes such as these is also optionally ignored during turn lane mapping.

Changeset Comment: Add missing turn lanes from satellite imagery https://github.com/mapbox/mapping/issues/153

Source: Bing/Mapbox

[jinalfoflia]

The imagery at some places is not very clear and at-times the turn-lanes are covered by cars. In situations like these Mapillary plugin can be used. If there is Mapillary imagery coverage in that area, they can used to verify the presence of turn-lanes.

Name of the plugin: Mapillary

Additionally, Strava global-heat cycle layer can used to verify if a particular lane is a cycle-way. tms[16]:http://globalheat.strava.com/tiles/cycling/color3/{zoom}/{x}/{y}.png

/cc @mapbox/team-data

[jothirnadh]

The new Turn lane mapping task of SF city is up for mapping. This task will include all the turn lanes from tertiary and above. If you face problems in loading the blocks please split it.

cc @mapbox/team-data

[Rub21]

@mapbox/peru-office is jumping on this task!,

Guys tengan en consideracion las intruciones.. :)

[jothirnadh]

The turn lane mapping tasks, DC task - 1 and Palo Alto task - 1 are completed and validated as well. The new DC turn lane mpping task is also up for mapping.

cc @mapbox/team-data

[jothirnadh]

Statistics of Turn lane mapping done in SF Peninsula

Duration: Jan 20th to Feb 10th

Team: @mapbox/team-data

Roads marked with turn lanes	Total
motorway	70
motorway_link	2111
trunk	432
trunk_link	116
primary	1317
secondary	1569
tertiary	518
Total	6133

cc @lxbarth and @mikelmaron

[ruthmaben]

How do we go forward with tagging these @mapbox/team-data

[planemad]

^ Not completely sure whats going on here. Would this be left|left;through @Andygol ?

[abhisheksaikia]

^I think this might be : left | merge_to_left;through @planemad @Andygol ?

[Andygol]

@ruthmaben

Would this be left|left;through

this is right tagging :point_up:

[Andygol]

@planemad
could you change changeset comment or create new task config for http://tasks.openstreetmap.us/project/22 ?

[Andygol]

Please pay attention in a case lanes=3 or similar. There is could be specified number of lanes in :forward and :backward directions

[talllguy]

DC 3 inch imagery

@abhisheksaikia DC GIS has an open data site with some additional resources, including 3 inch imagery from 2015, which was just posted four weeks ago. If we could somehow get this in JOSM, it'd be very useful. It is redacted around a few sensitive areas, e.g. The White House, but it is otherwise complete

• Searching for "orthophoto" on their open data site
• Dropbox link to the 2015 data

Redacted Areas

[ediyes]

Hey @Andygol What is the tag for this case?

cc. @mapbox/team-data

[talllguy]

@mapbox/team-data you guys crushed through this task, wow. Just looking through the data and some of the ones in the done areas still do not have turn lanes. What is the protocol to ignore?

http://www.openstreetmap.org/way/379685261/history

[Andygol]

@ediyes

What is the tag for this case?

turn:lanes=left|left;through|through

[talllguy]

@Andygol are the turn lane tags supposed to follow the paint on the road, or the intent of the paint? In other words, for routing purposes, would a turn:lanes=left|foo|foo tag indicate that at the end of that segment, the vehicle must turn left, or that the road marking underneath that segment indicates that there is a left turn lane ahead?

The reason I ask is while reviewing some of this tagging in DC I've found an instance with a left turn lane ends at a one-way (part of a dualized highway) that would be impossible. Though the paint indicates there is a left only restriction, the left only is beyond that intersection at the other part of the one-way pair. I thought it should be through until beyond the one-way pair, and then left after that.

[jothirnadh]

Statistics of Turn lane mapping done in DC

Duration: 1 day

Team: @mapbox/team-data

Roads marked with turn lanes	Total
motorway	20
motorway_link	8
trunk	34
trunk_link	3
primary	211
secondary	59
tertiary	35
Total	370

Observations:

• The imagery in not clear compared to SF which made it hard to identify turn lanes.
• The number of marked turn lanes in DC are much lesser (370) than the SF region (6133)

Next actions:

• [x] Creating a new Turn Lane mapping task in LA region by @abhisheksaikia

cc @planemad @lxbarth and @mikelmaron

[abhisheksaikia]

The reason I ask is while reviewing some of this tagging in DC I've found an instance with a left turn lane ends at a one-way (part of a dualized highway) that would be impossible.

@talllguy Regarding your query above^^, can you provide a link to the instance in OSM which will help in understanding the scenario better? Thanks.

[Andygol]

@talllguy

would a turn:lanes=left|foo|foo tag indicate that at the end of that segment, the vehicle must turn left

turn:lanes=left|| tagging indicates that from the leftmost lane we are allowed to move only in left direction when we reach an intersection/junction.

or that the road marking underneath that segment indicates that there is a left turn lane ahead?

if we have to prepare to change lane for a left turn from an extra lane we use turn:lanes=slight_left| beforehand of it

http://wiki.openstreetmap.org/wiki/Key:turn#Turning_indications

[abhisheksaikia]

New tasks for LA : http://tasks.openstreetmap.us/project/23 and Larger SF peninsula: http://tasks.openstreetmap.us/project/24 are up.

• Start working on LA mapping task first in the priority areas.
• Please split the tasks beforehand as the tasks might be too big in most cases.

cc @mapbox/team-data

[jothirnadh]

Just looking through the data and some of the ones in the done areas still do not have turn lanes. What is the protocol to ignore?

Thanks for flagging this out @talllguy , we are trying our best to identify all the turn lanes visible in Bing/Mapbox imagery from tertiary roads and above. By mistake we might be missing some due to the poor imagery quality. If you find any of the missing turn lanes, please flag them here so that we can add them.

[talllguy]

@Andygol I should have included a screenshot. Here:

segment link

So here I would say it should be through|right on the tagged segment, and then the segment in the middle would have a lane count of 1, with left only (assuming no uturns).

The question is if this is about mapping for routing directly.

[talllguy]

@jothirnadh I think I understand. If there isn't an explicitly denoted lane restriction visible on the imagery, you'd not tag it. Right?

[jothirnadh]

If there isn't an explicitly denoted lane restriction visible on the imagery, you'd not tag it. Right?

Yes @talllguy we are not tagging the turn:lanes which are not explicitly visible on the imagery. We are also not changing any of the turn:lanes marked by other contributors as they might have marked them using their local knowledge.

So here I would say it should be through|right on the tagged segment, and then the segment in the middle would have a lane count of 1, with left only (assuming no u turns).

What you said is true @talllguy, but thinking it in a mappers perspective it is hard to map these, as the turn directions differ from country to country. In US, a person travels on the right side of the road and coming to India (my native country) or London people stick to left. So it is hard to differentiate these rules. Even OSM wiki is not having much information on where to start and stop the turn:lane tagging.

According to my perspective it is important to add the tag left|right instead of through|right as the user needs to decide the lane beforehand, which he wants to continue his journey and it is what a routing engine (oce of the example) do. And tagging the next segment with left|through tag (not only left tag) is a good thing but not a necessary one as the other lanes are already marked with directions which will just be a redundant information added to any of the routing engine. Please let me know if I'm wrong or missing some information.

[jothirnadh]

I recently got a message from a OSM mapper saying that

A while back, I noticed that some service roads I added under Building 20 were moved by your colleague according to outdated satellite imagery. He seemed okay with me reverting these changes. I checked again today, and the service roads were moved again. I reverted the part of the changeset. Could you follow up with your team and make sure nobody else tries to move these service roads?

@mapbox/team-data It seems that the imagery is outdated in some regions. Don't try to align the roads while trying to add turn lanes. Check for the presence of GPS traces before aligning the roads to satellite imagery. You can also use the Recent Edits tool to highlight all the edits that are made in that region within one year to avoid further problems.

In the above GIF the features highlighted in green are recently modified once and the rest are from older changesets. Using this tool we can identify the recently changed edits and avoid aligning them.

cc: @planemad and @Andygol

[unsungNovelty]

While working on the LA turn lanes task, I came across a place where one single stretch with through|through symbols on the road. This have dotted lines and not solid lines like the native turn lanes. Can someone help me identify whether the below are actually turn lanes?

cc:/ @planemad

[jothirnadh]

Problems faced while mapping turn lanes in LA

Almost from the mid of January we are working on mapping turn lanes and so far we almost added ~6500 turn lanes in SF and DC. We got a clear understanding on how the turn lanes are marked in these regions, but coming to LA the scenario is a bit different. As per the discussion with the team I am drafting out the issues being faced while mapping turn lanes in LA.

• Confusion with parking lanes and turn lanes In SF and DC the parking lanes are well demarcated from the actual drive lanes with solid lines, but in LA there is no proper demarcation between drive lanes and parking lanes due to the absence of markers on the road. In this case the only way to determine parking lanes is to look for parked cars in the side lanes which is not a full proof method.

In the above case you can see there are cars parked on the sides of the road but those lanes are not separately demarcated as parking lots.

• Is it important to map small turn lanes In LA we are finding a lot of small turn lanes along the stretch of the road apart from junctions.

In the above GIF the road started with a junction and continued with a lot of minor turn lanes along the stretch. Are we supposed to map these turn lanes?

• Starting and ending of a turn lane

While validating blocks we came across many scenarios of starting a turn lane in wrong location. You can end a turn lane in a junction, but always start a turn lane where the exact turn lanes in the imagery starts.

cc @shvrm @lxbarth @maning @planemad @Andygol

[abhisheksaikia]

While splitting long stretch of road which is part of a route relation, JOSM validators reports aRole verification problem error. This is because a relation:route requires a role tag. JOSM validator flagged this error because we edited a way that is part of a route relation even though we just added turn:lanes:=*. See the wiki on relation:route: http://wiki.openstreetmap.org/wiki/Relation:route.

In most cases, the error can be ignored, but let's be very careful while splitting any route which is part of a relation and check any possible errors flagged during verification.

cc @maning

[maning]

@Andygol This is a single way with forward and backward turn lanes, but the starting point of the backward lane starts way before the starting point of the forward lane from the intersection to the north. I can't make it a dual-carriageway because it doesn't have a physical barrier in the middle of the road.

[maning]

Fixing the ^^^ above case, we split the road into 3 ways. Starting from the south we add the following tags:

• way 1: lanes=7, lanes:backward=4, turn:lanes:backward=left|||
• way 2: lanes=7, lanes:backward=4, turn:lanes:backward=left|||, lanes:forward=3, turn:lanes:forward=||right
• way 3: lanes=7,lanes:forward=3, turn:lanes:forward=||right

[Andygol]

Here is some tips how to add recently used tags. Just hold Shift pressed while choosing recently added tags from the Add value dialog. You may add recently used tags selecting it by mouse or using shortcut ⌘+⇧+[number]

[planemad]

Summarizing discussion from https://github.com/mapbox/mapping/issues/155

• The project focus is on turn lanes. So for completion we need correct addition of only turn:lanes, turn:lanes:forward, turn:lanes:backward. All other tags are extra information and not considered for project completion or validation.
• Only segments which have a turn lane needs to be tagged :point_up: . No turn lanes = no need for turn lane tag
• Adding lane= to help with style visualization and validation is ok, but not requirement for project completion. We can do lane mapping as a separate project for more efficient mapping and easier validation later.

cc @mapbox/team-data

[jothirnadh]

As per discussion with @pratikyadav @mikelmaron and @maning we are updating our workflow to add dual carriageways in case of physical separations on roads. At present, we have decided to add dual carriageways only for roads which are not part of any relation.

Dual-carriage way vs Fwd-Bkwd tagging

At some locations we are finding roads mapped by single carriageway while the imagery shows clear separation between roads.

When to add dual carriageway?

• Add Dual-carriage when
  • you see physical separation betweens roads
  • no relation is attached to the way.
• Add turn:lanes tag to both the ways.

This is added as a long term fix so that the present work of mapping turn:lanes does not become redundant in case dual carriageways are mapped in the future.

cc @mapbox/team-data

[Andygol]

Here I've spotted difference in Bing and Mapbox imagery. Bing imagery was created 1/3/2015-1/17/2015 date of Mapbox imagery unknown. I suggest that Bing is newer https://www.openstreetmap.org/#map=18/33.774646/-118.043975

Bing approvement from Strava heatmap

[Andygol]

I've updated alignment of highway :point_up: according Bing imagery + Mapillary https://www.openstreetmap.org/changeset/37530197

[jothirnadh]

Important We cleaned up 4206 empty turn lanes (turn:lanes=| or turn:lanes=|| ) in LA region with this cleanup workflow.

According to https://github.com/mapbox/mapping/issues/144#issuecomment-175635302 we only add turn:lanes if there is a turn lane with solid white markings on the road. We will not add empty turn lanes just for the turn lane visualization in JOSM.

cc @mapbox/team-data

[abhisheksaikia]

Capturing the estimated shipping dates for turn lanes mapping:

ESTIMATED :ship: DATES for turn lanes mapping task in LA for @mapbox/team-data :

• Progress till now: 67% done.
• Daily Progress: 4-5 %
• Estimated days remaining to complete the mapping task: ~8 working days.
• Estimated days required for validation: ~1 week (5 working days)
• Estimated time required to :ship: both mapping validation in turn lanes: ~3 weeks (25th March, 2016).

Next actions for the team in turn lanes mapping:

• [ ] Start with turn lanes mapping in larger SF area (upto San Jose).

cc @lxbarth @planemad @jothirnadh

[jothirnadh]

According to https://github.com/mapbox/mapping/issues/144#issuecomment-175635302 we only add turn:lanes if there is a solid white turn markings on the road. We will not add empty turn lanes just for the turn lane visualization in JOSM.

This issue is already been flagged and rectified but still finding it to be repeated by our @mapbox/team-data .

Overpass query: http://overpass-turbo.eu/s/eTL

@Rub21 can you follow this workflow and and use the above overpass query to clean this up in SF, DC and LA? It would be great if you can document your findings in this ticket.

[jothirnadh]

Statistics of Turn lane mapping done in LA

Duration: Feb 12th to March14th (still continuing)

Team: @mapbox/team-data

Users	tunr:lanes	turn:lanes:forward	turn:lanes:backward	Total
aarthy	11	11	10	32
andygol	706	434	415	1555
calfarome	1259	1191	1223	3673
Chetan_Gowda	20	28	29	77
dannykath	2073	1006	980	4059
ediyes	1301	946	936	3183
jinalfoflia	21	22	24	67
Jothirnadh	149	2107	2014	4270
karitotp	3017	3002	2895	8914
Luis36995	1118	322	306	1746
manings	32	21	25	78
nikhilprabhakar	92	68	58	218
oini	3	1	3	7
PlaneMad	1	2	3	6
pratikyadav	69	10	8	87
RichRico	1863	2233	2233	6329
ruthmaben	0	8	20	28
saikabhi	104	201	205	510
samely	2398	1164	1159	4721
srividya_c	2		2	4
Total	14239	12777	12548	39564

Expected time of completion: 25th March

[jothirnadh]

While @mapbox/team-data working on the mapping of turn lanes in LA two new scenarios were identified. They were:

Lanes with restricted access

These are the areas on streets which are restricted for vehicular traffic.

In the above cases the areas with markings on the roads are not considered as a lane

Reverse direction turn lanes

These are the lanes specifically categorised to take U-turn or reverse-turn.

These were listed in Turn Lane mapping guide, QA part. Keep us posted with new scenarios so that we can add it to the mapping guide.

[maning]

There were some roads that has turn lanes but don't have an actual intersection/junction. This doesn't make sense, if you see such roads make sure you add the road that intersects with them.

[jothirnadh]

Nice catch @maning, yes we are adding the roads at the actual junctions if they are missing.

[jinalfoflia]

Found this scenario where a separate road is traced from the major road. This is not required until there is a physical barrier between the roads. This turn lane can be a part of the existing road itself. So this road will have the following tags turn:lanes=left|||right.

[abhisheksaikia]

As per voice with @maning and @planemad, we are scaling down the turn lanes mapping task after the ongoing LA task is completed. The priority area in LA is almost completely mapped and validated. We will not work on the next SF peninsula task on turn lanes for now.

Next actions:

• [x] @mapbox/team-data to complete the remaining blocks in LA turn lanes mapping task and validate them.
• [x] @maning, @jothirnadh and me to cleanup data in the previously completed tasks in SF and DC.
• [x] @jothirnadh and me to put up a detailed summary of the stats on the turn lanes added till now.
• [ ] @jothirnadh and me to discuss the next comms on turn lanes: blog and diary posts and put forward a timeline for getting them out.

cc @lxbarth @mikelmaron

[dannykath]

While I was validating turn:lanes:* in L A
I found a highway: https://www.openstreetmap.org/way/13320233/history that doesn't match with the satellite imagery:

Bing Imagery

Mapbox Imagery

Which satellite imagery should I work with?

@mapbox/team-data

[aaronlidman]

@dannykath - I grew up in this area, it is changing a lot right now, but the Bing imagery is correct.

Tiger also shows the correct location.

[dannykath]

thanks @aaronlidman :+1:

[jothirnadh]

Fixed it as per the bing imagery @dannykath https://www.openstreetmap.org/way/13320233/history#map=18/33.71805/-117.73640

[abhisheksaikia]

The LA turn lanes has been completely mapped and validated by @mapbox/team-data. :100: :rocket:

As discussed above, we are going to scale down our turn lanes mapping effort and stop working on it for now.

IMMEDIATE NEXT ACTIONS:

@maning, @jothirnadh and me to cleanup data in the previously completed tasks in SF and DC.

We are working on cleaning up the previous turn lanes data in SF and DC using overpass turbo. Estimated time: 3 days

@jothirnadh and me to put up a detailed summary of the stats on the turn lanes added till now.

@jothirnadh and me to put up the stats by end of this week by working with @planemad: derive observations from the statistics and wrap up the LA turn lanes mapping effort.

[oini]

Statistics of Turn Lane mapping in LA:

• Duration: February 12th to March 29th
• Total turn lanes added: 51,385

Overall Statistics for Turn Lane mapping tasks:

• Team: ~12
• Average hours per day per person: ~5
• Total number of working days: 48
• Total hours: 2880 hours

Task	Area (square kilometers)	Existing total turn lanes in each city	Turn lane density (per square kilometer)	Percentage of total turn lanes added by Team Mapbox	Turn Lanes added by team in 1 hour	Time taken to add 1 turn lane (minutes)	Percentage of turn lanes starting with left
SF	278.66	1,780	6.39	51.97%	12.33	4.86	70.38%
DC	206.78	745	3.6	81.88%	114	0.53	67.54%
LA	7,534.92	54,161	7.19	94.87%	321.15	0.19	89.71%

Conclusion:

Thus we can make the following conclusions based on our observations for the mapping tasks in SF, DC and, LA:

• Currently our team can add ~321.15 turn lanes in an hour
• Average density of turn lanes in an US city is ~5.73 per square kilometer
• Average area of a task for an US city is ~2673.45 square kilometers
• Average percentage of turn lanes in an US city that require mapping is ~76.24%
• With our current speed, it should take the team ~74 days to add turn lanes in top 10 US cities
• An average of ~75.88% of all turn lanes begin with left. Thus having a plugin that automatically sets the first lane as left and provides other facilities to enhance the speed of mapping even further would be ideal

cc @abhisheksaikia @jothirnadh @planemad