A few months back in the OSM India community, we were curious to know how much of the trunk network of National Highways has been mapped compared to the official statistics released by the government.

We started off by aggregating all the statistics we could find from various official sources on the road lengths for different types of roads into a common spreadsheet.

Next was to calculate the corresponding length of roads in each state mapped on OSM. To do this, I used the osm-coverage tile reduce processor with added support for Admin-1 regions from natural earth vectors.

All it takes to run this for the Indian subcontinent is:

npm install

node download.js --all

node index.js --area=[56,-12,116,42] > output.json

To generate per highway tag road length in kms for each state in the bbox. The processing should not take more than 5 minutes.

These numbers were used to compare with the official figures and generate a list of states where the national highway coverage needs to be improved.

Try it out for your area and see if it helps detect missing highway networks. The code is in the regions branch of the processor: https://github.com/mapbox/osm-coverage/tree/regions

Happy to hear feedback on how it worked and how the processor can be improved.