More Housing & Less Parking near MBTA Stations

Locate a parcel

Search any Greater Boston address or click the map. The parcel under your point is fetched live from MassGIS.

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Customize unit mix & rents

% of unitsAvg rent ($/mo)

Studio

1 BR

2 BR

3+ BR

Affordable units (≤ 60% AMI)

Outcome · municipal parking requirement

The municipal requirement is the starting ratio (zoning code or local parking policy). TDM strategies above determine how far below it we can right-size, while still meeting demand. The slider auto-fills from the selected parcel's jurisdiction; you can override.

Municipal parking requirement (spaces/unit) — pick a parcel

1.50

Baseline (zoning) —

After location + TDM —

Spaces avoided —

Map layers MBTA rapid transit MBTA Commuter Rail MBTA bus stops Bluebikes ½-mile site buffer MBTA Communities (3A) districts 3A transit half-mile radii Boston zoning subdistricts Selected parcel (MassGIS)

Subway / Light rail Commuter rail Bus Ferry Bluebikes 3A district Boston zoning Parcel

No site selected

Pick a parcel to see live calculations.

Transit access

Pick a parcel

Transit access tier appears here

Driving — vs. regional avg

CO₂ emissions — vs. regional avg

Costs saved from parking — vs. municipal req

Additional units enabled — from reclaimed floor area

Scenario	Miles / HH / day	CO₂ kg / HH / day	Parking spaces / unit
Regional baseline	—	—	—
At this location	—	—	—
With strategies	—	—	—

Within ½ mile

No site selected.

This tool is an MVP screening model for Boston and all 177 MBTA Communities in Massachusetts — built on top of state and city open data so any developer, planner, or policy professional can estimate the construction-cost and land savings of right-sizing parking on a real parcel. It extends the framing of David Reed's blog post How To Build More Housing with Less Parking into something interactive, and borrows the location-efficiency framework from TransForm's GreenTRIP Connect.

What it estimates

Predicted parking demand vs. the municipal requirement
Construction-cost savings (≈ $65K per structured space, Boston midpoint)
Square footage freed for additional housing, open space, or amenities
Vehicle Miles Traveled (VMT) per household per day and daily CO₂ emissions

The intended use case: help a development team or municipal staffer decide how far below the local parking baseline a project can right-size, and quantify what that unlocks — fewer sunk costs in structured parking, more capital available for units, and more land left for housing rather than asphalt.

Three scenarios

Regional baseline. A "typical" MA suburban location: 28.5 VMT/HH/day (MAPC Vehicle Census + NHTS Northeast). Parking baseline = 1.6 spaces/unit.
At this location. Adjusted by a transit access tier based on the closest MBTA stop (subway, light rail, commuter rail, or bus). Each tier maps to a fixed parking-demand reduction and VMT reduction drawn from CAPCOA T-3, MAPC Perfect Fit Parking IV, and Boston Article 80 PTDM guidance. Sites in downtown Boston get a small additional bump.
With TDM strategies. Layered Vehicle Trip Reduction (VTR) ranges from the FHWA TDM rubric, the VTPI TDM Encyclopedia, and other peer-reviewed sources — see the full TDM evidence base. Total VTR is capped at 50% per FHWA / CAPCOA guidance.

Right-sizing parking

The right-sized parking ratio is the outcome — not an input. It starts from the municipal requirement (zoning code or local parking policy, auto-filled per jurisdiction) and is reduced by:

rightsized_ratio  = muni_req × (1 − location_reduction) × (1 − tdm_VTR)

location_reduction = transit_tier_parking_red + 0.05·downtown_flag
tdm_VTR            = min(0.50, Σ selected strategies' midpoint VTR)
spaces_avoided     = (muni_req − rightsized_ratio) × units
costs_saved        = spaces_avoided × $65,000                (Boston structured midpoint)
sqft_freed         = spaces_avoided × 330 sf                 (structured space incl. drive aisle)
additional_units   = floor(sqft_freed × 0.85 / 950 gsf)      (net-to-gross × gross sf/unit)

A strong location plus a credible TDM package determines how far below the municipal baseline a project can right-size. Every space avoided is roughly $65,000 in construction cost and ~330 sq ft of floor area that can be converted to more housing on the same footprint — typically ~1 additional unit for every ~3.4 spaces removed at 950 gsf/unit (MAPC Perfect Fit IV; ULI residential floorplate norms).

Transit access tiers

Tier is determined by the closest qualifying MBTA stop within ½ mile. Rapid transit = subway or light rail. Frequent bus = ≥ 6 peak trips/hour (≤10-minute headway). Reductions apply before TDM strategies.

Tier	Condition	Parking red.	VMT red.
0	Limited transit (nothing qualifying within ½ mi)	0%	0%
1	Bus or commuter rail ≤ ½ mi	10%	5%
2	Frequent bus ≤ ¼ mi or commuter rail ≤ ¼ mi	20%	12%
3	Rapid transit ≤ ½ mi	35%	22%
4	Rapid transit ≤ ¼ mi	50%	30%

Downtown Boston adds +5% parking and +3% VMT. Income / affordability mix and TDM strategies stack on top.

From tier to outputs

location_vmt        = baseline_vmt × (1 − tier_vmt_red − 0.03·downtown) × income_mult
strategy_vmt        = location_vmt × (1 − tdm_VTR)
ghg_kg_per_day      = vmt × 0.378
rightsized_parking  = muni_req × (1 − tier_parking_red − 0.05·downtown) × (1 − tdm_VTR)

Municipal requirement is auto-filled from the parcel's jurisdiction (Boston, Cambridge, Somerville, and other MBTA Communities have their own local parking policies). You can override the slider.

Data & methodology sources

TDM effectiveness ranges, parking-demand evidence, geospatial layers, and emission factors.

FHWA — Integrating Demand Management into the Planning Process (FHWA-HOP-12-035) — the canonical TDM effectiveness rubric used to set per-strategy VTR ranges
Victoria Transport Policy Institute — TDM Encyclopedia — peer-reviewed strategy summaries, including parking management, parking pricing, and unbundling
CAPCOA — Handbook for Analyzing GHG Emission Reductions (2021) — category-level and bundle caps; the 50% total-VTR ceiling
MAPC — Perfect Fit Parking (Phases I–IV) — Metro Boston residential parking demand by transit access & affordability share; ~30% of off-street spaces sit vacant at peak demand
Shoup — The High Cost of Free Parking & Parking Cash-Out: Eight Case Studies — parking pricing, cash-out, unbundling
Martin & Shaheen — Impacts of Carsharing on Household Vehicle Holdings — each car-share vehicle replaces 9–13 private vehicles
ITE — Shared Parking, 3rd Edition — mixed-use shared-parking demand overlap
MBTA Communities Law (G.L. c. 40A §3A) — parking caps in compliance districts: 1.0 (≤1BR) / 1.5 (2BR) / 2.0 (3+BR)
MBTA GTFS — schedule + stops (rapid transit, commuter rail, bus, ferry)
Bluebikes GBFS — 600+ station network
MassGIS — MBTA Communities (3A) District Atlas — compliant zoning districts statewide
MassGIS — Level 3 Property Tax Parcels — statewide assessor parcels, fetched live on click
Analyze Boston — Zoning Subdistricts — BPDA Article-by-Article subdistrict polygons
City of Boston — Bicycle Level of Traffic Stress (BLTS) — 19,623 segments scored 1–4 (city only)
MAPC — Massachusetts Vehicle Census — baseline VMT
HUD FY2025 Income Limits — Boston-Cambridge-Quincy MSA AMI tiers
EPA 2024 LDV GHG inventory — 378 g CO₂e/mile

What this is and isn't

This is an MVP screening tool — designed to support conversations with developers, municipalities, and community advocates about right-sizing parking and prioritizing transit-served sites. It is not a substitute for a project-specific traffic study, MEPA filing, or Article 80 / TAPA transportation review.

Each strategy in step 3 carries a Vehicle Trip Reduction (VTR) range drawn from peer-reviewed and federal-agency literature on residential TDM. This tool applies the midpoint of each range and then caps the total at 50% per CAPCOA bundle guidance — no residential development can credibly claim more than a 50% reduction from voluntary strategies.

Category ranges & sources

Category	Per-strategy VTR (range)	Cap	Primary sources
Active transportation Bike room, e-mobility, bikeshare subsidy, programming, Pedal & Park	1–15% / strategy	30%	FHWA TDM Rubric; VTPI — Bicycle & Pedestrian Improvements; CAPCOA T-21
Public & private transit MBTA pass subsidy, TMA / shuttle, real-time info	1–15% / strategy	25%	FHWA TDM Rubric; VTPI — Transit Encouragement; TCRP 95 (Ch. 13)
Car-share & ride-hail EV car-share on-site, dedicated ride-hail zone	5–10% / strategy	18%	Martin & Shaheen — Carsharing Impacts; VTPI — Carsharing; CAPCOA T-15
Parking pricing & supply Unbundled parking, shared parking, parking cash-out	3–20% / strategy	22%	Shoup — The High Cost of Free Parking; ITE Shared Parking (3rd ed.); MAPC Perfect Fit Parking; Parking Cash-Out (Shoup, 1997)
Bundle total	—	50%	CAPCOA bundle cap; FHWA "high transit" upper bound

Why categories are capped

Strategies overlap in the residents they serve — a household with a bike room + transit pass + car-share membership doesn't drive 3× less than one with just the bike room. Per-category caps prevent double-counting within a mode, and the 50% bundle cap mirrors what the empirical literature (FHWA, CAPCOA, MAPC) supports as a credible upper bound for a single development's voluntary measures.

Boston-specific evidence

MAPC's Perfect Fit Parking studies (Phases I–IV, 2017–2023) found that residential off-street parking in Metro Boston is overbuilt by ~30% at peak demand, with parking supply, transit-accessible jobs, and affordability share as the three strongest predictors of demand. The Phase 4 study reported average supply of 1.45 spaces/unit against average demand of 0.92 — a gap of ~$33,000 per unit in unused structured parking. This tool's parking-demand formula is calibrated against those findings.