Methods and Framework

An eight-stage data pipeline, three theoretical frameworks, and the formulas behind the redistribution pressure score, Compound Vulnerability Index (CVI), and Alternative Plan review flag.

Summary

This site currently preserves a reproducible GTFS-operational model of 128 Los Angeles Metro station groups while regional SCAG map records and local implementation records are reviewed. Local ordinances, HCD/state review, unincorporated-county timing, independent-city records, and planned-transit treatment remain separate implementation records.

  • 8 pipeline stages
  • 128 named station groups (from 471 qualifying stop records) 471 qualifying stop records: 454 Metro rail GTFS stops + 17 G Line / Orange Line BRT stops. Deduplicated by platform and station hub. G Line BRT incorporated May 2026. The current dataset includes the operational D Line Phase 1 stations at Wilshire/La Brea, Wilshire/Fairfax, and Wilshire/La Cienega. The Metro J Line remains excluded per LA City DCP (November 2025).
  • 20+ source datasets ACS, CalEnviroScreen, TCAC/HCD, Cal Fire, LA City Planning, Metro GTFS, LA County assessor, HPOZ/HCM records.
  • EPSG:2229 spatial projection California State Plane Zone 5. Used for all area calculations. Census joins use majority-overlap rule.

Methodology overview

The Analytic Pipeline

Stage 1 downloads General Transit Feed Specification (GTFS) data for all LA Metro stops and creates 0.5-mile transit-oriented development (TOD) buffer zones. Each buffer defines the spatial extent of one modeled TOD station area.

Stage 2 overlays Historic Preservation Overlay Zone (HPOZ) and Historic-Cultural Monument (HCM) boundaries and computes local historic-resource coverage for each station. Stations exceeding 0.10 (10% local historic coverage) are flagged for Alternative Plan review.

Stages 3–4 join census tract demographics (ACS 5-year estimates) and apply the TCAC/HCD opportunity layer.

Stages 5–6 compute redistribution pressure scores and incorporate CalEnviroScreen 4.0.

Stages 7–8 add carceral infrastructure proximity, fire perimeter overlap, and compute the Compound Vulnerability Index (CVI). All pipeline code is reproducible from the source data in data/raw/.

Limitations

This analysis is descriptive. It identifies communities at risk based on existing spatial and demographic conditions; it does not predict developer behavior, rate of change, or individual resident outcomes.

Local implementation status is treated separately from the station model. Los Angeles City’s Low-Rise and phased implementation ordinances, SCAG map records, HCD/state review, independent-city actions, temporary exemption claims, and unincorporated-county timing can diverge. Exposure remains a screening indicator, not a prediction of project approvals or displacement outcomes.

Census tract joins introduce geographic approximation. Tracts that span station boundaries are allocated to the station with the majority overlap, which may misallocate demographic weight at the margins.

What this model includes / not yet includes

Included in this analysis

  • Station grouping and deduplication (128 groups from 471 qualifying stop records: 111 rail groups from 454 GTFS stops + 17 G Line BRT groups)
  • Modeled 0.5-mile station-area buffers
  • Historic-resource Alternative Plan review flag (HPOZ / HCM coverage)
  • Redistribution pressure score (historic conflict, opportunity inverse, renter rate)
  • Compound Vulnerability Index (6 components)
  • Fire perimeter overlap (Eaton and Palisades fires)
  • Renter rate, housing cost burden, and opportunity-level indicators

Not yet modeled

  • 200-foot adjacency intensifier (parcel-level distance to access points)
  • Parcel-level distance to qualifying pedestrian access points
  • SB 35 / SB 423 streamlining eligibility by project type
  • RSO-site redevelopment configurations (parking / nonresidential portions)
  • Localized implementation pathway by jurisdiction
  • LA City phased implementation boundaries and temporary exemption timing
  • HCD review letters or HCD-approved TOD Alternative Plans
  • Transit-agency-owned land standards

Implementation status is time-sensitive. HCD requires local SB 79 ordinances and TOD Alternative Plans to be submitted for review. Los Angeles adopted a phased implementation approach by City Council vote on March 24, 2026. A draft Phased Implementation Ordinance (CPC-2026-1798-MSC) was released April 17, 2026; CPC hearings were held May 6–7, 2026. This site does not yet model parcel-level phased implementation eligibility or LA City's localized Low-Rise / phased implementation system.

  • 471 qualifying stop records
  • 128 named station groups after deduplication
  • 4.1 stops per group (average)

Deduplication note

A Note on Station Counts

SB 79 creates one TOD zone per qualifying transit stop. This analysis covers two transit categories. For Metro rail, LA Metro's GTFS feed contains 448 individual stop records: separate entries for each platform, direction, and entrance. A multi-platform station, such as Union Station, appears in the GTFS as dozens of distinct stops.

The rail component deduplicates to 111 named station groups by clustering stops within 400 meters with identical station names. Each group has one TOD buffer. This matches the policy intent: SB 79's zone is the half-mile circle around the station, not around each platform.

The G Line / Orange Line BRT was incorporated in May 2026, adding 17 named station groups from 33 directional GTFS stop records. The D Line Phase 1 extension (Wilshire/La Brea, Wilshire/Fairfax, and Wilshire/La Cienega, operational since October 2023) was incorporated in May 2026, bringing the rail total to 111 named station groups. This brings the total to 471 qualifying stop records deduplicated into 128 named station groups. The Metro J Line remains excluded based on LA City DCP's November 2025 report because it lacks full-time dedicated bus lanes. Additional planned or qualifying bus corridors remain under review.

The deduplication methodology is conservative. However, some Metro stops that share a name but serve different lines at significant distances may be incorrectly merged. The reproducible pipeline in data/raw/ includes the full clustering logic.

Why it matters for comparisons

LA City DCP's phased implementation model (2026) uses 145 administrative TOD zones — reflecting LA City boundaries, the statutory qualifying-stop definition, and a K Line Northern Extension update (4 new zones). Other published SB 79 analyses may use different station-group definitions. None of these counts are wrong; they serve different analytical purposes.

When comparing this analysis to others: raw stop counts will always be higher than grouped station counts. The comparison unit for SB 79 purposes is the station group (one TOD buffer), not the individual stop.

  • Pressure 0.40 + 0.40 + 0.20 Weights: historic conflict (0.40), opportunity inverse (0.40), renter rate (0.20). Range 0–100.
  • CVI Σ(weight × component) Six components, all normalized 0–100. Equal weighting after normalization.
  • Historic-resource review flag local historic-resource coverage > 10% (hcm_area_acres + hpoz_area_acres) / tod_area_acres > 0.10

Formulas

The Three Key Formulas

Redistribution Pressure Score

0.40 × historic-resource coverage + 0.40 × inverse opportunity score + 0.20 × renter share

Range: 0–100. Historic conflict reflects local historic-resource coverage. Opportunity inverse reflects lower access to high-opportunity resources. Renter share reflects the share of occupied units that are renter-occupied.

Compound Vulnerability Index (CVI)

CVI = Σ(weightᵢ × componentᵢ)

Six components: CalEnviroScreen burden, renter rate, housing cost burden, redistribution pressure, carceral infrastructure proximity, poverty rate. All components normalized 0–100 before weighting.

Historic-resource review flag

local historic-resource coverage = (HCM area + HPOZ area) / TOD-zone area

Stations with more than 10% locally designated historic-resource coverage are flagged for Alternative Plan review. This is a screening indicator. No HCD-accepted TOD Alternative Plan is reflected in this dataset. Los Angeles has begun localized SB 79 implementation through Low-Rise and phased implementation ordinances; this analysis has not yet incorporated those local implementation boundaries.

What to watch for

The pressure score weights are calibrated to give equal weight to historic conflict and opportunity inverse. This reflects the theoretical claim that both mechanisms (who can shift capacity, what opportunity exists in receiving zones) are equally determinative of redistribution outcomes.

Alternative weighting schemes are possible. Doubling the renter_rate weight (0.40 / 0.40 / 0.40, renormalized) produces marginally higher scores for South LA stations. The ranking of top-20 stations is stable across all tested weighting schemes.

  • Roy et al. Displaceability by Design, 2025 Primary theoretical grounding for the Displaceability Index.
  • Roy & Zablotsky, eds. Beyond Sanctuary, 2025 Normative and analytical frame for protection mechanisms, displacement governance, and reciprocal obligations in Los Angeles geography.
  • AEPLRC After Echo Park Lake Research Collective, 2022 Continuum of Carcerality. Informs the carceral-proximity component of compound vulnerability.
  • Olivarius AHR 2019 / Necropolis 2022 Insurance, credit, legal access, and rebuilding finance as recovery-capacity factors. Full citation appears in the annotated bibliography.

Theoretical frameworks

How Each Framework Grounds the Analysis

Displacement studies and critical geography provide the interpretive frame for this site. The analysis draws on work about transit investment, displacement pressure, environmental burden, tenancy precarity, housing cost stress, enforcement geography, and historic-resource policy. These frameworks guide how screening indicators are interpreted; they do not prove that a specific policy caused displacement at a specific station.

Disaster recovery and capital access inform the Eaton Fire case study. Insurance, credit access, legal support, and rebuilding finance are treated as recovery-capacity factors that can affect whether households rebuild, sell, or remain displaced.

Methodological sources also shape the spatial analysis, including counter-mapping methods, nuisance-abatement exposure research, and scholarship on property, race, and ownership regimes. Public scores remain screening indicators intended to identify places for closer review.

Limitations of each framework

Roy et al. was written for a different geographic context. Its component weights were calibrated for a specific study area and have been adapted here without revalidation. The direction of each component is theoretically grounded; the relative weights are not independently validated.

Beyond Sanctuary is a normative and theoretical anthology, not an empirical study of Los Angeles. Its concepts — surplusification, deportability as discipline, the ruse of sanctuary — apply by structural analogy. The leap from refugee and homeless governance to transit-corridor displacement requires explicit acknowledgment that the scales and conditions differ.

The Continuum of Carcerality framework is primarily qualitative. Operationalizing it as a density measure introduces precision that the original framework does not claim.

Immunocapitalism is an argument about mechanism, not a predictive model. Using it to frame insurance underinsurance as a structural dynamic rather than individual bad luck is justified; using it to predict specific household outcomes is not.

Bibliography

The annotated bibliography contains legislative, scholarly, data, and policy sources with full citations, influence rankings, and notes on integration with the analysis pipeline.

Download annotated bibliography Return to previous page

Data Sources

This analysis draws from eight public datasets. Source data are not proprietary to this project; links go to each organization’s official dataset or program page.

Source Organization Role in this analysis
SB 79 (Chapter 512, Statutes of 2025) California Legislature Defines all spatial parameters: 0.5-mile TOD buffer radius, 10% historic-resource Alternative Plan threshold, capacity-neutrality requirement, qualifying transit stop typology, and effective date.
LA Metro GTFS Los Angeles County Metropolitan Transportation Authority (LA Metro) 471 qualifying stop records (454 Metro rail + 17 G Line BRT) defining the 128 named station groups and their 0.5-mile TOD buffer zones.
American Community Survey 5-Year Estimates (2019–2023) U.S. Census Bureau Renter rate, poverty rate, housing cost burden, and linguistic isolation by census tract; primary inputs to the Compound Vulnerability Index and redistribution pressure score.
CalEnviroScreen 4.0 California Office of Environmental Health Hazard Assessment (OEHHA) Cumulative environmental burden by census tract; environmental burden component of the Compound Vulnerability Index.
TCAC/HCD Opportunity Map California Tax Credit Allocation Committee (TCAC) and CA Dept. of Housing and Community Development (HCD) Opportunity classification (Highest Resource → Highest Poverty) by census tract; opportunity-inverse component of the redistribution pressure score.
Historic Preservation Overlay Zones (HPOZ) and Historic-Cultural Monuments (HCM) City of Los Angeles, Department of City Planning Polygon boundaries used to compute local historic-resource coverage per TOD zone; stations with ≥10% historic coverage flagged for Alternative Plan review.
Wildfire Perimeters — NIFC FIRIS (2025) National Interagency Fire Center (NIFC) / California Dept. of Forestry and Fire Protection (CAL FIRE) 2025 Palisades, Eaton, and Hurst fire perimeters; fire-adjacent screening indicator per TOD zone used in compound vulnerability analysis.
LA City Zoning and Parcel Data City of Los Angeles, Department of City Planning — GeoHub Base parcel geography and zoning classifications for TOD zone spatial joins and Very High Fire Hazard Severity Zone (VHFHSZ) analysis.

The annotated bibliography contains full citations for all legislative, scholarly, data, and policy sources. Download bibliography.