Wishlist: Road classification data in Telangana

I think it would be great to convince the Telangana authorities to release OSM licence-compatible open map data that shows the State Highways, Major District Roads and Other District Roads in Telangana.

I have been working to connect “isolated” villages and other built-up areas to the general road network (and resolve Osmose errors), but without SH, MDR and ODR data, I have no clue whether to use highway=secondary, highway=tertiary or highway=unclassified.

Your help is appreciated. I made this post so I wouldn’t forget what we need to do together to make the OSM map of Telangana better.

In general, any road that serves as the main connection to a village (even a very small one) will deserve at least highway=tertiary. That reserves the two more minor classifications (highway=unclassified and highway=residential) for the smaller roads in the village or that connect out from it through farmland.

To decide between highway=secondary and highway=tertiary I would suggest making that decision based on the size of the communities that the roads connect. If a road only connects between two tiny villages or from a large village to end in a small village, then highway=tertiary is more appropriate. If it connects between two large villages, then highway=secondary is probably more appropriate. Figuring out that size threshold is up to the Indian community, but highway=unclassified is unlikely to be correct for the main roads connecting anything but an isolated dwelling.

I assume highway=tertiary as the default for roads between settlements.

How easy or hard is it to request usable open map data from the Indian state governments? I am interested in mapping SH, MDR and ODRs in Telangana.

In terms of highway classification, the recommended tagging scheme for India is documented on this Wiki page: India/Tags/Highway - OpenStreetMap Wiki

Essentially, ODRs are highway=tertiary, MDRs are highway=secondary, SHs are highway=primary and NHs are highway=trunk. Other village roads would be highway=unclassified.

On the topic of official government open map data, there is the PMGSY National GIS data which is compatible with the ODbL. There’s more details on this GitHub repo: GitHub - datameet/pmgsy-geosadak: PMGSY National GIS - Open Data

The raw data itself can be downloaded from the official page, though it may be geoblocked and accessible only from India: PMGSY National GIS - Open Data PMGSY GeoSadak

However, there are numerous data accuracy issues with the PMGSY data, either outdated or outright incorrect numbering/naming of SHs/MDRs/ODRs. There’s been some discussion about this on the OSM India Telegram group, some folks there may be able to provide more details about it: Telegram: Contact @OSMIndia