Brighton and Hove roadside pass
- What was built
- One survey pass of roughly a kilometre of Brighton seafront and the streets around it, driven on a single day. 2,008 frames, 4,146 positioned features and 3,411 carriageway defect reads, delivered as one layer per asset class in British National Grid with a data dictionary and stable feature identifiers, and browsable in the capture viewer with the photograph behind every value.
- What was measured
- Legible-value precision of 98.0%, 245 of 250, on a seeded reproducible stratified sample, with a 95% confidence interval of 95.4% to 99.1%.
- What it does not establish
- That figure measures whether values we claimed to read were read correctly, and nothing else. It is not a recall figure, so it says nothing about what the pass missed, and positional accuracy has not yet been measured against survey-grade ground truth. Coverage is what was driven: there is no claim to national coverage here.