Assumed inputs
One standardized green roof bus shelter is modeled. Values below are current defaults — they will be updated as real measurements arrive from pilot monitoring and as agency-aligned coefficients land via SOW Task 2.
| Shelter typology | JCDecaux 4-section Grimshaw (and Solar/Narrow variants) |
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| Canopy | ~70 sq ft (14 ft × 5 ft, 4-section) |
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| Green-roof coverage | Adjustable, default 100% of canopy. Scales retention & cooling linearly (placeholder). |
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| Substrate depth | 4 in extensive green roof media (shallow, lightweight, sedum-forward — not an intensive/deep-soil roof) |
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| Plant palette | Sedum-forward, NY-appropriate, low-maintenance |
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| Retention rate | ~50 gal / shelter / 1″ storm at 100% coverage (literature default) |
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| Cooling effect | ~6°F reduction within 10 ft radius at 100% coverage (Boston reference, treat as rough) |
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| Install cost (placeholder) | $1,400 – $7,000 per shelter retrofit (wide range, to be refined) |
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Agency lineage
Where possible, lenses align with frameworks already in use at NYC agencies, to avoid duplicate measurement burden and to slot into existing decision-making processes (NPCC standardization work, OMB capital-project intake).
| Heat | NYC CEJ heat metrics (Helen Cooper). Green roof bus shelters as a practical test case for the CEJ framework. |
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| Stormwater | NYC MOUA conservation metrics (with NY State Soil & Water District) + NYC DEP Green Acres standards. |
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| Biodiversity LOW CONF. | Pollinator habitat connectivity, as a gap-crossing stepping-stone score per shelter (landscape-connectivity method — Saura & Pascual-Hortal 2007; anchored to solitary-bee foraging ~250–300 m — Gathmann & Tscharntke 2002). A siting heuristic, not a measured benefit: green-roof-as-habitat evidence is weak and ~70 sq ft may be below the effective stepping-stone threshold. Patches = NYC parks (DPR) + community gardens (GreenThumb) + green infrastructure (DEP); street-tree canopy still to be added. |
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| Air quality | Foregone in this evaluation phase — shelter-scale sensors are physically too large and approval timelines do not fit the current pilot window. |
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Three-scale impact
Each lens reports impact at three scales so policy memos can quote the framing that matches their argument:
- Under-shelter — immediate footprint per shelter (retention, cooling) for a single-stop story.
- Street level — cumulative effect across the selected scenario shelters.
- Community — neighborhood-scale framing that ties retention to flooding patterns or cooling to high-HVI rider exposure.
Scope
- All sheltered stops are eligible. The scenario operates on every existing bus-shelter stop (≤25 m shelter–stop match); the viable-typology gate has been removed. Stops with no shelter are shown for context (binary sheltered/unsheltered) but excluded from the scenario.
- Structural capacity — which JCDecaux typologies can carry a green-roof load is still to be confirmed with the team; for now all sheltered stops are modifiable.
- Single-shelter scope requires clicking a shelter on the map.
- Borough scope aggregates shelters by borough. Finer-grained NTA / Climate Strong Communities geographies are future work.
Open work
- Biodiversity lens — pending Columbia measurement capacity + partner institution coordination.
- NTA & Climate Strong Communities geographies for a finer-than-borough scope.
- Formal DEP "green acres" translation for stormwater community-scale row.
- OMB capital-project key indicators + Technical Appendix B alignment.
- Helen (CEJ) & Kiana (MOUA) metric-table integration once permission to share is confirmed.
- Designed PDF tear sheet (currently uses browser print stylesheet).
Data sources
- Bus routes / stops / ridership: MTA
- Bus shelters: NYC DOT (JCDecaux inventory)
- Heat Vulnerability Index (HVI): NYC DOHMH 2024 (by MODZCTA)
- Flood Vulnerability (FSHRI): NYC MOCEJ 2024 (by census tract)