Imagery coverage
How much of the road network is actually photographed?
Street-level imagery coverage is the denominator every other measurement on this site depends on. It is not looked up from a table — it is measured directly against each city’s OpenStreetMap road network.
The measurement instrument
Coverage is measured with Mapillary’s vector coverage tiles (tiles.mapillary.com/maps/vtp/mly1_public), which report image density without ever downloading image bytes. For each of the 1,034,197 road sample points across 9 cities already built (sampled at 50m spacing), the pipeline will query the nearest coverage tile and record whether nearby street-level imagery exists.
The one documented data point in the literature (Randhawa et al., arXiv:2410.19874) states only that “Japan, Thailand and some parts of India showed good coverage while Pakistan, Iran and Indonesia showed notably sparse coverage” — no city-level ranking exists anywhere. This project’s coverage-tile query is the actual measurement, not a lookup.
Why coverage isn’t a filter
The 14-city candidate pool (see /cities) was fixed before any coverage check. If cities had been chosen for good coverage, the study could never observe a badly-covered city and the bias question would be unanswerable by construction. Coverage is measured as an outcome, and at least one low-coverage, low-economic-tier city is deliberately kept in the final sample even if its coverage turns out poor.
Coverage map
Not yet measured
Map coming once Mapillary coverage measurement completes. This requires a MAPILLARY_TOKEN environment variable that has not been provided to this repo yet — the pipeline fails loudly rather than silently if it is unset. No coverage percentage exists for any city right now; nothing below is a placeholder number standing in for a real one.
see docs/data_sources.md
Licensing note
Mapillary imagery is contributor-licensed CC BY-SA, but Mapillary’s Developer Terms separately restrict “reproducing the Services.” This project’s decision: any future Street Explorer view hotlinks Mapillary’s own short-lived thumb_*_url values returned live by their API — the browser fetches bytes directly from Mapillary’s CDN. No image bytes are ever downloaded to disk, committed to git, or re-served from UrbanLens India’s own storage.