{"version":"v2","rowGrain":"One English Census 2021 LSOA in the reference CSV","referenceModel":"reference_independent with reference housing mapping","nulls":"Blank CSV cells and JSON null mean unavailable; they are not zero.","inputs":"Census TS044 housing and TS045 household car availability; 2021 counts","modelled_vehicles":"Household cars/vans: 1*n1 + 2*n2 + 3.5*n3plus in reference scenario; not an observed exact count","modelled_off_street_pct":"100 * modelled off-street vehicles / modelled household cars-vans; unvalidated","modelled_garage_use_pct":"100 * modelled inside-garage vehicles / modelled household cars-vans; unvalidated","street_or_other_vehicles":"Modelled household vehicles minus modelled off-street vehicles; cannot be assumed on street","provision_proxy_pct":"Housing-weighted EHS garage + other off-street provision percentage; household denominator","fallback_households_pct":"Commercial and mobile housing categories using proxy mappings","household_difference":"Published TS044 total minus TS045 total; housing mix is scaled to TS045 total","reference_decile":"Equal-LSOA-weight national rank of unrounded reference off-street share; 1 low, 10 high; ties kept together","sensitivity":"Min/max over 27 explicitly defined scenarios; not confidence intervals or exhaustive bounds","unavailable":["observed_off_street_pct","observed_garage_pct","residential_road_km","street_vehicles_per_km","vehicle_miles","collisions","rate_per_100000_miles"],"allScenariosRows":911385,"groupJsonModelColumns":["offStreetPct","garageUsePct","streetOrOtherVehicles","decile","modeledVehicles"],"sourceFiles":"See summary.json for source URLs, archive paths, observation dates and SHA-256 hashes","limitations":{"geography":"England; Census 2021 LSOAs","reference":"2021 household counts with 2024 EHS provision rates; no annual backcast","householdReconciliation":"Scale TS044 type counts proportionally to each TS045 household total. Preserve both published totals and their difference.","joint":"Independent within each LSOA by default. Positive/negative rank couplings preserve both margins, concentrating more cars in higher/lower-provision types; they are stress tests, not joint Census observations.","capacity":"For n vehicles, garage-use probability u and d extra spaces, garage-provision off-street capacity is u[min(n,1)+min(max(n−1,0),d)]+(1−u)min(n,d). Other off-street provision accommodates min(n,o). Apply these to synthetic household counts.","residual":"Total modeled household vehicles minus off-street vehicles. This is street-or-other demand, not observed street parking. No per-km measure without matched residential centreline geometry.","deciles":"Rank eligible English LSOAs by unrounded modeled vehicle off-street share, equal area weights. Cutpoints at ceil(N×d/10). Ties stay together in the lower decile; counts may differ. Re-rank separately for every scenario. Deciles are exposure candidates, not collision findings.","ranges":"27 variants = 3 capacity/use scenarios × 3 housing–car associations × 3 type mappings. Range is a sensitivity envelope, not a probability or confidence interval, and does not span every possible model.","mapping":"House categories use EHS detached/semi/terraced rates, although Census includes bungalows. Purpose-built flats use the EHS population-weighted low/high-rise mix. Converted categories and commercial flats use converted-flat rates; mobile homes use all-dwelling rates. Alternative mappings substitute bungalow/flat extrema and 0–100% provision for commercial/mobile categories.","validation":"National NTS benchmark held out from construction; numerical proximity is not validation. No aligned independent LSOA overnight vehicle-use validation, and no local error, correlation or holdout score is claimed.","interpretation":"A housing/car-derived predictor cannot independently identify a parking effect beyond those ingredients. EHS rates describe provision, not capacity or use. Garage-use assumptions are not estimated from observed local behaviour."}}