Mapping missing roads in cities of Philippines

[GRABOSM]

Objective: Grab team has mapped these regions in the past and this time we are going through the existing road geometries and add the missing ones if any. We'll be reviewing and mapping the following features: missing roads, road classification, and check for intersection configurations and alignment accuracy.

By Ramon FVelasquez - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=25551639

Regions we are reviewing/mapping:

Starting with the following city [cities]:

• Bacolod, PH
• Aklan, PH
• Baguio, PH
• Balanga, PH
• Cagayan de Oro, PH
• General Santos, PH
• Iloilo, PH
• Legazpi, PH
• Metro Zamboanga, PH
• Pampanga, PH
• Subic, PH
• Tarlac, PH
• Tacloban, PH
• Sorsogon, PH
• Olongapo, PH
• Dumaguete, PH
• Dagupan, PH
• Cabanatuan City, PH
• Bohol, PH
• Baguio, PH
• Cebu City, PH
• Metro Manila, PH
• Davao, PH
• Naga City, PH
• Binalonan, PH

Workflow: We'll be following the same workflow as mentioned in our wiki - https://github.com/GRABOSM/Grab-Data/blob/master/Data%20Improvement%20Projects and https://wiki.openstreetmap.org/wiki/Grab#Process_Flow

Validation: We'll be following the validation guidelines mentioned in our wiki: https://wiki.openstreetmap.org/wiki/Grab#Quality_Process

Changeset Comment: Mapping missing roads and road attributes https://github.com/GRABOSM/Grab-Data/issues/42

Source: MAXAR -- we would refer to others if need be.

Filter: None

Plugins: None

Edge cases: None at the moment, we'll post it as a subsequent comment if need be.

Team involved: The Grab Data team

Do reach out to us if you have any questions or suggestions on the same. Happy Mapping!

cc: @jinalfoflia

[GRABOSM]

While mapping in the city Pampanga we came across so many ways classified as Footways/Paths which are mapped back in 2015. Upon checking these features, it seems like polygons are wrongly tagged with Highway tags. Here are few examples for your reference way 339889280, way 349416531 are classified as highway = path instead of landuse. Please find the screenshots below for more clarification.

Example 1: way 339889280

Example 2: way 349416531

We have similar issues across the city. Please suggest if we should retain the data as it is or go ahead and change it? cc: @govvin @maning

[govvin]

If you double-check on the examples you provided, there are landuse polygons covering the area of interest you described.

w349416531 is covered by a landuse, w339664430 w339889280 is covered by a landuse, w313525437

As these appear to be rice paddy fields, IMO, those paths are perhaps more appropriately tagged as footways.

[maning]

While mapping in the city Pampanga we came across so many ways classified as Footways/Paths which are mapped back in 2015.

These were mapping efforts made by the local government unit in the area through their disaster risk reduction initiative.
Please contact the mapper directly if you have concerns about the edits.

As these appear to be rice paddy fields, IMO, those paths are perhaps more appropriately tagged as footways.

From imagery, I agree that paths can be downgraded to footways. HOWEVER, without local context, its difficult to be sure. Please contact the local mappers before changing any primary tags. I see that your team have started editing these features mostly improving geometry (like here).

[GRABOSM]

Thank you @maning and @govvin for the insights on this. We will reach out to the individual mappers and take next actions accordingly. Until then, we will keep the data as it is.

[DP24PH]

Kindly reach-out to all mappers regarding this supposed missing road-turned-closed/cordoned area in #WashingtonPlacePH since upon last checking, I have placed a note on the grass landuse area where I have warned not to map any roadway as shown on aerial imagery due to [a] barricaded vacant lot area [placed by WPHOA Security]. I have reverted immediately as a measure, and kindly verify first before mapping where the aerial imagery seems outdated (possible cause of mapping error).

Here's the imagery below (courtesy of Maxar) where the thin green (metal) and thick black (concrete) lines represent the wall):

AFFECTED changeset: 107423937

CC: @GRABOSM

[GRABOSM]

@DP24PH, thank you for the clear explanation of the cordoned area, and for reverting the wrong edits. Please do let us know if there is any other imagery source we can consider for mapping in these areas. We will ensure that the team is informed of the same.

[dolfandringa]

Hello grab people, I really like your efforts to update the OSM maps, but your changeset Changeset: 108662477 I disagree with. It looks like you based it exclusively on bing/maxar data (as per the tag), but those roads were thoroughly misclassified. You classified them as secondary roads, and renamed it to Pamplona, Sibulan, Valencia road, as if it is a major road connecting those towns. It is not. Anyone driving from Pamplona to Valencia will use the coastal highway. This is a 90% unpaved road, that only links a few small mountain barangays and sitios, and isn't used by anybody not living directly there (most people from Valencia and Sibulan don't even know it exists). Especially the last stretch over the mountains to Valencia is exclusively a track or footpath that can only be driven by serious dirt bikes or on foot. Please take care when you reclassify roads that you actually know the area or can clearly see from satellite footage what it looks like, and look at the history of a road. Especially when looking at the history, you can easily see that people already classified roads before manually from local knowledge and you can prevent undoing hard work done by others.

[dolfandringa]

Can you guys please check for past changesets when you mark roads that you don't know. This changesets is absolutely wrong and people keep marking it as a secondary road. It is only a hiking trail that nobody would ever consider taking except the people high in the mountains who have no other choice or people with expert trail bikes or hikers. It is not accessible for anyone else. Most people in vlanecia don't even know it exists. Going to any bigger barangay (santa agueda) or town (Pamplona) is much much faster along the highway through tanjay. You are bound to send people into trouble by these changes because the trail gets really steep and nasty rocky and muddy. httpss://www.openstreetmap.org/changeset/111641410?xhr=1#map=13/9.2511/123.1078

[TagaSanPedroAko]

I would like to address some concerns with data quality I found in Batangas City, which I have noticed lately. So far, I find a lot of problems with road alignment. I have set up imagery offsets to use in improving road alignment, but I found the majority of editors who edited in the are not using them, resulting in all the data problems I've seen lately. I'm currently working on fixing these, reverting the edits that badly changed road alignment based on GPX and accompanying imagery offsets.

[GRABOSM]

I would like to address some concerns with data quality I found in Batangas City, which I have noticed lately. So far, I find a lot of problems with road alignment. I have set up imagery offsets to use in improving road alignment, but I found the majority of editors who edited in the are not using them, resulting in all the data problems I've seen lately. I'm currently working on fixing these, reverting the edits that badly changed road alignment based on GPX and accompanying imagery offsets.

@TagaSanPedroAko thank you for reaching out and the feedback. Our team did use GPX traces as the primary source and were using Maxar the imagery as it was clearer than bing and it seemed to be aligned to the GPX traces. You can see that in the screenshot below:

https://user-images.githubusercontent.com/38514914/144829232-422310ef-075d-4775-b7a6-3fe19968eb88.mp4

The traces were aligned with the imagery (Maxar) so we decided to go ahead with it.

When it comes to the offset you mentioned, if you have set it to your imagery, we won't be able to see it unless it's mentioned in the changeset either as a tag or comment. If you have these values it'll be helpful if you can share this data with us so that we can align the satellite imagery accordingly.

Nonetheless, we have taken this feedback and are working on re-aligning the roads the look misaligned. Please let us know if you have any questions.

[GRABOSM]

Can you guys please check for past changesets when you mark roads that you don't know. This changesets is absolutely wrong and people keep marking it as a secondary road. It is only a hiking trail that nobody would ever consider taking except the people high in the mountains who have no other choice or people with expert trail bikes or hikers. It is not accessible for anyone else. Most people in vlanecia don't even know it exists. Going to any bigger barangay (santa agueda) or town (Pamplona) is much much faster along the highway through tanjay. You are bound to send people into trouble by these changes because the trail gets really steep and nasty rocky and muddy. httpss://www.openstreetmap.org/changeset/111641410?xhr=1#map=13/9.2511/123.1078

@dolfandringa, thank you for bringing the hiking trail to our notice. But, we have modified the alignment of the highway as per the latest satellite imagery in this changeset and the classification highway=secondary was created by some other mapper in 2020 with multiple versions kindly refer: https://pewu.github.io/osm-history/#/way/838405630 and Let us know if you have any questions. We have responded to your changeset comment, please do let us know if you have more questions. Thank you!

[TagaSanPedroAko]

Also another thing I'm seeing with edits in Batangas City is the driveways, some of which are tagged as highway=residential or are too short to be useful for navigation.

In addition, I'm also noticing problems with edits on sections of a future bypass road (STAR Tollway-Pinamucan), some of which are upgrades to existing local roads. I just managed to fix some edits that realigned them to pre-reconstruction state, noting that those are based on outdated imagery (the road is under construction but still not visible on available imagery).

[TagaSanPedroAko]

For Maxar Standard, I added a new offset, applicable to Poblacion, south of D. Silang (P. Burgos to D. Atienza) and west of D. Atienza. Offset measurement is 2, -1.5.

For Bing, multiple offsets are available across Batangas City (just look for those ending with "Bing 2021", as these are the latest available). Most areas covered, except around Ilijan.

[GRABOSM]

For Maxar Standard, I added a new offset, applicable to Poblacion, south of D. Silang (P. Burgos to D. Atienza) and west of D. Atienza. Offset measurement is 2, -1.5.

For Bing, multiple offsets are available across Batangas City (just look for those ending with "Bing 2021", as these are the latest available). Most areas covered, except around Ilijan.

@TagaSanPedroAko Thank you for suggesting these, we have shared this with the team and it'll help us better map this region.

[TagaSanPedroAko]

Also related, I'm noticing issues with road alignment around Lipa dating from September. I can trace the edits behind the problem to some Grab editors. From the problems I'm seeing, certain of your editors should be reminded to check for imagery offsets before realigning everything (the existing imagery is badly offset, while the roads align well with GPS tracks). I'm also considering another edit to revert some of the most problematic edits, especially on the major roads.

[GRABOSM]

Also related, I'm noticing issues with road alignment around Lipa dating from September. I can trace the edits behind the problem to some Grab editors. From the problems I'm seeing, certain of your editors should be reminded to check for imagery offsets before realigning everything (the existing imagery is badly offset, while the roads align well with GPS tracks). I'm also considering another edit to revert some of the most problematic edits, especially on the major roads.

@TagaSanPedroAko We put mapping on hold in Lipa after we discovered the offset issue, please look into this issue https://github.com/GRABOSM/Grab-Data/issues/105, for the edits you are referring to, we'd request you not revert but share the offset with us and we'll ensure that it's aligned accordingly.

Through the feedback, we realized that there are quite a few places that have imagery offset in the Philippines and you also have the information about them. The issue is that offsets you set for the imagery are limited to your system, we are wondering if there was a way we could document this in a wiki or if there is an existing resource that we could refer to? This would help all the mappers who map here. We would love to collaborate with you on this.

[TagaSanPedroAko]

You can find existing offsets at the Imagery Offset Database (IOB), accessible through '''Get imagery offset''' in JOSM. I've already uploaded some offsets to IOB for multiple areas in Lipa, especially for Bing imagery. Bing and Maxar generally has the same images for Lipa, but Bing has higher-resolution pics.

[GRABOSM]

You can find existing offsets at the Imagery Offset Database (IOB), accessible through '''Get imagery offset''' in JOSM. I've already uploaded some offsets to IOB for multiple areas in Lipa, especially for Bing imagery. Bing and Maxar generally has the same images for Lipa, but Bing has higher-resolution pics.

@TagaSanPedroAko Thank you so much for sharing this with us, we will make this a part of our workflow, so that in the future if a region has some offset, we will be aware of it and will ensure that we map using that offset.