Mapping and Aligning road network in Taiwan based on new Mapbox imagery and Strava

[jothirnadh]

Objective:

Add/ realign the roads in Taiwan using Mapbox satellite imagery and Strava

Freedom Plaza, source: Wikipedia

Here is the breakdown of cities we are going to concentrate map:

Major roads alignment as per Mapbox imagery

City name	Task link	Start date	End date	kms of road	# persons worked
Taipei & New Taipei	#26	21/09/2016	21/22/2016	694	12
Taoyuan City	#27	22/09/2016	22/09/2016	434	16
Hsinchu	#28	22/09/2016	22/09/2016	341	8
Taichung	#29	22/09/2016	23/09/2016	1187	19
Yilan	#30	23/09/2016	23/09/2016	507	17
Tainan	#31	23/09/2016	23/09/2016	860	9

Minor roads alignment as per Mapbox imagery

City name	Task link	Start date	End date	kms of road	# persons worked
Taipei & New Taipei	#32	27/09/2016	27/22/2016	832	10
Taoyuan City	#34	27/09/2016	28/09/2016	1283	10
Hsinchu	#35	28/09/2016	28/09/2016	517	10
Taichung	#40	28/09/2016	29/09/2016	3640	20
Tainan	#41	29/09/2016	29/09/2016	2253	20
Yilan	#42	29/09/2016	29/09/2016	1843	10

Major and Minor roads alignment as per Mapbox imagery

City name	Task link	Start date	End date	kms of road	# persons worked
Kaohsiung	#43	29/09/2016	30/09/2016	4097	20
Taipei, New Taipei & Taoyuan Outskirts	#44	30/09/2016	03/10/2016	2566	18
Taichung Outskirts	#39	03/10/2016	03/10/2016
Hsinchu Outskirts	#45	03/10/2016	03/10/2016
Tainan Outskirts	#46	03/10/2016	04/10/2016
Yilan Outskirts	#47	04/10/2016

Major and minor road alignment as per bing imagery

City name	Task link	Start date	End date	kms of road	# persons worked
Chiayi County - 1	#48	04/10/2016
Chiayi County - 2	#49	04/10/2016
North Changhua County	#50
South Changhua County	#51
Chiayi County - 3	#52
Taipei north	#53
Xinwu District	#54
South Fengling Township	#55
Hualien County	#56
South of Taiwan	#57

Note: Please do follow the workflow mentioned in the tasking manager for👆 tasks

Team: @mapbox/team-data along with the OSM-Taiwan community

Features to map: All major roads, from tertiary and above

Available data sources: Mapbox imagery and Strava cycling and walking heatmap

Workflow:

• Load Mapbox Satellite Imagery as base map in JOSM
• Load Strava Heatmap of cycling and walking for reference : click this link to load in JOSM
• Load the selected block of tasking manager in JOSM and add/realign and merge highways as per Mapbox satellite imagery
• Use inverse filter highway=motorway|trunk|primary|secondary|*link|motorway_link|tertiary for showing major roads
• Use inverse filter highway=residential|unclassified|service for showing minor roads
• Use inverse filter highway=motorway|trunk|primary|secondary|motorway_link|*_junction|tertiary|trunk_link|residential|unclassified|service for showing all types of road
• Split the block into smaller blocks if the data is too huge

Changeset comment - Add/realign streets #https://github.com/mapbox/mapping/issues/233

Changeset source - Mapbox Satellite, Strava heat map

cc: @mapbox/team-data

[maning]

This intersection looks like it should be connected from southeast to northwest Should we connect?

• Also this intersection: https://www.openstreetmap.org/#map=18/25.032661/121.495897

[maning]

@Supaplextw

[Supaplextw]

It seems there is a connect road from the lane to the main street, both for cars and pedestrians

[Supaplextw]

https://www.openstreetmap.org/#map=18/25.032661/121.495897 @maning I'm not sure which intersection do you mean. Could you use a mark to pin down?

[maning]

@Supaplextw This one: http://osm.org/go/5i1pZoyjO--?m=

[Supaplextw]

@maning Ya. A connect road and the entrance to the parking lot for the commercial building.

[maning]

Ya. A connect road and the entrance to the parking lot for the commercial building.

@Supaplextw Thanks! Connected now.

[jothirnadh]

We completed 64% 🚀 of the Taipei task in 3 hours with a team of 12 mappers, which implies each person is completing 5 blocks per hour on an average 💥 . There is a total of 1158 blocks in Taiwan tasks yet to be mapped. As per estimated stats with current workflow, we need 3 days for mapping and 3 more days for validation with 20 active mappers (including Peru).

• [x] Work on providing regular feedback to the OSM-Taiwan community through this ticket
• [x] We are mapping only tertiary and above roads for now, but in future, we can think of other tasks for mapping/aligning minor roads as well
• [x] There are three more cities in the south of Taiwan which we will hit after the Satellite imagery is updated.

cc: @mapbox/team-data

[maning]

These two sections of a motorway overlapped, they have different layer tags, so I assume they are on different levels/height from the ground. @Supaplextw Can you confirm?

Way ID below:

• https://www.openstreetmap.org/way/229193806/
• https://www.openstreetmap.org/way/312878259

[Supaplextw]

Ya, it's a overlap expressway in the city.

[unsungNovelty]

Only one road is traced for layer=3 and layer=2 in the above case. But is separately drawn after the intersection. What should I do in the case? Should I trace a separate road or is there a particular reason why only one road is trace? Can you please help @Supaplextw?

• Way ID: - https://www.openstreetmap.org/#map=19/25.06097889283218/121.5885193048383

[maning]

OMG! Taiwan!

Please watch out for the layer tags.

[maning]

location: http://osm.org/go/5i1pdRfkQ--?m=

The tertiary looks like a dual-carriageway and should not connect to the single traffic signal base on imagery.

[maning]

To verify layer for complex interchanges, use the Layer checker paint style in JOSM. View > Map Paint Styles > Map pain preferences.

Colour codes based on various layers are as tabulated

Color	Layer No.
Green	1
Cyan	2
Purple	3

Beyond layer 3 the colour remains same (Purple).

[abhisheksaikia]

@Supaplextw Is this an elevated U-turn or an error. Can you please go through it? Link: https://www.openstreetmap.org/way/364187901/history#map=19/25.02317/121.27970

[jothirnadh]

We completed Taipei mapping task and added/aligned 694 Kms of roads all together in 2 days 💥 . This is a huge lift off road network improvement in Taiwan and is never possible without the support of OSM-Taiwan community 👏 . It would be great if the community can help us in validating the task and give us consistent feedback to improve present workflow.

Here is the breakdown of Taipei mapping effort:

• Total Kms of roads improved : 694 Kms
• Total time spent on this task : 5hrs
• Total mappers involved : 12

If we continue mapping with such certainty we can even add/align minor roads (residential, unclassified and service roads) as a secondary round of mapping phase in Taiwan.

Next actions:

• [x] We started off mapping in New Taipei which is expected to complete by tomorrow
• [x] Post the stats of New Taipei task once it is done 🚀
• [x] @mapbox/peru-office, it will be great if you can join us in the upcoming tasks to hit this much faster 😉

cc: @lxbarth @srividyacb @maning @jacquestardie

[bsrinivasa]

• Way Id - https://www.openstreetmap.org/way/440544583

This way is running over a river and it has no layer tag or bridgetag. Can someone with local knowledge check if the data is correct around this road?

Also, the roads at the interchange seems to have no proper layer tags tagged for the ways.

The bridge=viaduct is tagged as layer=4 at one side and layer=5 for the opposite side which runs for a long distance.

Highways at Interchange with no proper `layer=` tags*

It would be great if anyone from the community can help us on these issues.

Here are the way-ids.

• https://www.openstreetmap.org/way/291356413
• https://www.openstreetmap.org/way/311562578

cc @Supaplextw

[ridixcr]

help me please

overlaping between the way and buildings when aligning the way according Strava and Mapbox Satellite

https://www.openstreetmap.org/#map=18/24.14457/120.677613 http://cfn-tasking-manager-staging-vpc-387856624.us-east-1.elb.amazonaws.com/project/29#task/338

cc. @jothirnadh @maning

[assanges]

Hi, it's me assanges. And I guess some of you all had heard of me already.

And I still active on this specific area which I lived hereby, of which I noticed Mapbox analyst had edited again. haha Please kindly take my Strava activity (https://www.strava.com/activities/714223008) or GPX uploaded (https://www.openstreetmap.org/user/assanges/traces/2261480) for reference, and attached official file as well. Many thanks!

For http://www.openstreetmap.org/note/722825

For http://www.openstreetmap.org/note/722830 http://www.openstreetmap.org/note/722834

[abhisheksaikia]

Taiwan update and next actions:

The @mapbox/team-data have almost completed aligning major roads in these 4 cities: Taipei, New Taipei, Hsinchu and Taichung ahead of schedule 💥 .

Next actions in Taiwan realignment:

• [x] Align major roads in next two cities where satellite imagery is already rendered: Tainan and Yilan; @jothirnadh to create the tasks and update this ticket.
• [ ] Create a task for the last city: Kaohsiung City once the satellite imagery is rendered.
• [x] Start validating these tasks once major road realignment in all the 7 cities is completed.
• [ ] Start off with aligning minor roads (once major road realignment is over in all the 7 cities): start with Taipei and evaluate based on the time required to realign minor roads in Taipei.

cc @shvrm @maning @srividyacb

[jothirnadh]

Align major roads in next two cities where satellite imagery is already rendered: Tainan and Yilan; @jothirnadh to create the tasks and update this ticket.

The tasks for Tainan and Yilan are created. Jump into these tasks once we are done with Taichung

cc: @mapbox/team-data

[jothirnadh]

overlapping between the way and buildings when aligning the way according to Strava and Mapbox Satellite

@ridixcr if the buildings are overlapping with the imagery, make sure that the buildings are aligned to imagery as well. It is documented in the workflow as well.

[jothirnadh]

@Yurasi I came across a road which you aligned as per Strava heat map Link

The alignment is supposed to be made as per the Mapbox satellite imagery but not Strava heat map. Just use Strava heat map for support when you are not sure of the road alignment/existence. The reason for this is Strava heatmap consists of the GPS traces from walking and cycling profiles, which lie on the sides of the roads most of the time. In the above case, there is a separate cycling track next to the tertiary road where Strava activity is more. Please make a note of this issue in further mapping @mapbox/team-data .

[bsrinivasa]

Hello @assanges ,

Thank you for validating our edits during adding/aligning the roads in Taiwan. We used the existing Mapbox imagery for realigning roads in that area. We tried editing it back but seems like it's hard to track things on the ground, as the imagery is a bit old. It would be great if you can revert/make changes of our edits with your local knowledge so that the map is up to date. Thank you for providing the various sources. Will keep these issues in mind going forward. It would be awesome to have your feedback and participation in helping us validate the task https://github.com/mapbox/mapping/issues/233.

[maanyaumashaanker]

Could someone please confirm how far does this road having https://www.openstreetmap.org/way/279154065 as its way Id continue?

cc @Supaplextw

[assanges]

Hi @bsrinivasa ! Thanks for your fast reply! And yeah, I agreed that it's hard to revert after many edits without field research, and I shall take this from here, a big big thanks again for you and your teammates' effort!

[kagami3421]

Hello @maanyaumashaanker . The secondary road ends tertiary road refenences Y4(宜4) , therefore the road in your screenshot should be unclassified road.

[abhisheksaikia]

We completed adding/aligning more than 4000 Kms of major roads all together in 3 days in 6 cities in Taiwan💥 . There has also been continuous validation and help from the Taiwan community while we have mapped. A massive thanks to the community for their efforts from @mapbox/team-data 🚀. It would be great to continue working with the community in the validation work in these 6 cities. The team will also move ahead with aligning minor roads in Taipei once the validation of these 6 cities is completed.

Here is the breakdown of Taiwan mapping effort:

• Total Kms of roads improved : 4023 Kms
• Total time spent on this task : 3 days
• Total mappers involved : 19

Next actions:

• [x] Start validating the 6 tasks along with the community.
• [x] Create a new task for Kaohsiung City for major road realignment.
• [x] Start aligning minor roads in Taipei

cc: @Supaplextw @assanges @kagami3421 @lxbarth @jacquestardie

[abhisheksaikia]

Diary post on Taiwan mapping progress is out: http://www.openstreetmap.org/user/saikabhi/diary/39543

[unsungNovelty]

@mapbox/team-data, While validating the task in Yilan, I came across some issues in the data.

Case 1:

Let's make sure the road is aligned to the centre of the road in satellite imagery

Case 2:

_Make sure the motorway_junctions are realigned to where the road splits_

Case 3:

While realigning roads in junctions, always make sure the road that crossings the junction is also realigned in a straight line.

Let's make sure we are checking all these above cases and updating appropriately while validating the data.

[abhisheksaikia]

As a reminder to everyone already validating, or jumping in on validation process of major roads in Taiwan -

• we've completed validating 5 cities, and right now validation is underway in Tainan
• remember that we're using Mapbox imagery to align roads - make sure the same imagery is used when validation as well
• when using Strava (cycling or walking traces), often the traces fall to the side of the road. Only use Strava as a guidance source, rather than the primary source for realignment

Bing vs. Mapbox Imagery misalignment example

cc @mapbox/team-data

[abhisheksaikia]

There are cases of satellite imagery distortion in Mapbox. Distortion can be identified by sudden curves in long stretches of highways which are generally straight. Let's keep an eye out for such issues while aligning and validating blocks. In case, Mapbox appears distorted double check with Bing and Strava traces to verify the distortion.

cc @mapbox/team-data @jacquestardie

[geochetan]

Many highways are overlapping on lot of buildings. The buildings doesn't match to any imageries (Mapbox/Bing). The user CYUT10128068 added these buildings 11 months ago.

The testing buildings:

Here in this junction, the buildings are serially added.

The actual buildings looks completely different. (Look right side)

How we are moving with this kind of overlappings? and ensure the quality of the data.

@assanges @Supaplextw @mapbox/team-data

[kagami3421]

Hello @chtnha . The account is shared by some students from CYUT university(朝陽科技大學). Their doing also preplexs us. Such as drawing buildings without considering real situation.

Now the best treatment jsut ingore them. Seriously , fix the overlapping will annoy and increase your work.

[Supaplextw]

The editing from CYUT ignore the real building situation. We're thinking about mass deletion of there building due to lack of response and fixing.

[assanges]

I agreee with kagami3421. These improper edit shouldn't set you back in efforts on alignment, leave them to we the local community to fix it.

[Rub21]

Hi Everyone , Usually in alignment we should move many nodes and we need to be sure where we worked and where missing realignment to check it I am using this JOSM style which help me to check out where I modified the objects, the differences between the existing modified objects style is that this works only for modified nodes, and is more clear to me.

[littlebtc]

FYI, I am adjusting the Wenxin Road (文心路) in Taichung again, as the train viaduct is building in the center of the road and the imagery is not updated for that.

[littlebtc]

In the imagery, the Wenxin Road near Wenxin Park:

The actual street view now after the viaduct is completed:

So I have to re-align the road and the railway viaduct to match the current status. Also, the orthophoto suffers offsets caused from building heavily :(

[jothirnadh]

We completed aligning more than 10,368 Kms of minor roads all together in 3 days for 6 highly populated cities of Taiwan💥. Massive thanks to the OSM-Taiwan community for their support from @mapbox/team-data 🚀. It would be great to continue working with the community in the validation work in these 7 cities. The team will move ahead with aligning minor and major roads in the outskirts of these cities.

Here is the breakdown of Taiwan mapping effort:

• Total Kms of roads improved : 10,368 Kms
• Total time spent on this task : 3 days
• Total mappers involved : 20

Next actions:

• [ ] Take help from the community to validate the tasks.
• [ ] Complete the road alignment task in outskirts of top 7 cities (Taichung, Yilan, Tainan, Hsinchu still pending)
• [ ] Create new tasks for areas outside newly rendered satellite imagery for road realignment.

cc: @Supaplextw @assanges @kagami3421 @lxbarth

[Yurasi]

Hi team! I have a question, must we change the highway=* tag? i.e. We find some street with highway=service tag, but they should be clearly highway=residential.

But also there are some of them tagged as highway=road (which are motorable), and I'm wondering how much important is change them because of the navigability of the city through all the motorable roads.

cc: @Supaplextw @assanges @kagami3421

[maning]

@Yurasi, lets focus on realigning for now. The community can then review the road class.

[jothirnadh]

Great work @mapbox/team-data and OSM Taiwan community 👏 . We are almost done with aligning roads in the top 7 cities of Taiwan where new Mapbox imagery was added. Let's keep up the zest and continue the mapping quest to the other parts of Taiwan as well 🚀 .

In the other parts of Taiwan, the Mapbox imagery is limited to zoom 17. So, from now on let's stick to Bing imagery for mapping. Will post more updates on the upcoming tasks. Let's start off with Chiayi County - 1 task for now.

Thanks for coordinating with us so far OSM Taiwan community 🙇 , it would be great if the community members can validate the completed tasks and give us feedback to improve our workflow.

[Andygol]

In some places Mapbox and Bing imagery is shifted. You may align them using Strava heatmap as reference.

@maing: This is not an issue on flat areas so they should only adjust for areas within rugged/sloping terrain.

I use 👇 this values for http://tasks.mapbox.com/project/47#task/73 and http://tasks.mapbox.com/project/47#task/31 Bing offset - -0.00; 4.33 Mapbox offset - -0.15; 5.82

[kagami3421]

Hello @Yurasi . Your change is correct and helps me a lot. But changing road class is our task I should do.

Those service road is tagged by me when starting contributing OSM in 2014~2015. I've considered the Lane (巷) should tagging as service road , but other guys say my tagging schema is wrong. Therefore I changed my schema after according to OSM wiki.

[unsungNovelty]

@mapbox/team-data - In case you find any alignment/offset issues in the Satellite Imagery that is being used for a task, always cross check the area with Strava heat map for aggregated GPS traces before adding/modifying the data. Below are the two Strava heat map TMS layers that can be added to JOSM:

• Strava Cycling - tms[16]:http://globalheat.strava.com/tiles/cycling/color3/{zoom}/{x}/{y}.png)
• The Strava Global heat map - tms[3,17]:http://globalheat.strava.com/tiles/both/color2/{zoom}/{x}/{y}.png

[maning]

Taiwan Bing imagery offsets at http://offsets.textual.ru/map

Currently, we provide imagery offset adjustment through the specific TM when we use Bing. There is a db for storing and sharing imagery offset that is integrated in JOSM. Should we update the Imagery Offset DB so the community can use it too?

@Supaplextw @assanges @kagami3421 @littlebtc Is this something that the OSM-TW community use for their editing with Bing?

cc/ @Andygol @jothirnadh @abhisheksaikia @srividyacb @planemad

[Andygol]

@maning I ❤️ ☝️

as I know this offset db is used in Vespucci - https://wiki.openstreetmap.org/wiki/Vespucci

[littlebtc]

I was using the JOSM offset plugin when dealing with Bing.

[luiswalter]

The way to use the alignment layer Bing are not very good in this area - http://tasks.mapbox.com/project/71#task/1203

It was worked with Satellite MapBox which alignment is very good.

What are the values to consider higher value to align properly? Bing o Mapbox satellite

@Rub21 @jothirnadh @maning