States Are Overriding Local Zoning to Force Housing Near Transit — Here's What's Actually Happening

For half a century, the pattern was almost universal: American cities built rail lines, then surrounded the stations with parking lots and single-family houses. The result was billions in transit capital spent moving people past land uses that generated almost no riders. That pattern is finally breaking — not because local planning boards changed their minds, but because state legislatures are overriding them. In the last four years, Massachusetts, Colorado, Washington, and California have passed laws that force municipalities to allow multi-family housing near transit stations, whether the neighbors like it or not. The politics are messy, the enforcement is uneven, and the equity questions are unresolved. But the ridership stakes are enormous.

Why the Zoning-Transit Mismatch Matters

Transit-oriented development, or TOD, is a simple idea with stubborn arithmetic behind it. The standard TOD radius is a quarter to a half mile around a station — roughly a 10-minute walk, or about 500 acres in the half-mile ring. What sits inside that ring determines whether a rail line is a transportation backbone or an expensive commuter novelty.

The Transit Cooperative Research Program has repeatedly found that TOD residents use transit 2 to 5 times more often than residents of auto-oriented neighborhoods. TCRP Report 102 pegged the commute-mode-share bump at 20 to 40 percent within a half mile of rail. Every 1,000 new TOD housing units within a half mile of a rail station generates an estimated 500,000 to 1 million additional annual boardings — enough to move the needle on any mid-sized system's farebox.

The Parking Math That Kills Projects

The other half of the equation is what you don't build. Structured parking costs $30,000 to $75,000 per space, and minimum-parking requirements have quietly made low- and mid-rise apartments infeasible near stations for decades. Removing those minimums is often the single change that flips a TOD project from red to black. This is why the newest state laws focus as much on what cities cannot require as on what they must allow.

The 3Ds Still Rule

UC Berkeley's Robert Cervero, whose work anchors most of the TOD research canon, found that households within a half mile of California rail stations take transit for roughly 30 percent of trips, compared with 5 to 8 percent in auto-oriented areas. But the ridership only shows up when the "3Ds" — density, diversity of uses, and design — are all present. Density alone, dropped into a hostile street grid, doesn't do it. TransitCenter has hammered a related point: TOD generates ridership only when it's paired with high-frequency service. Density near infrequent trains is just expensive housing.

Massachusetts: The MBTA Communities Act and the Milton Precedent

The most consequential state law is the MBTA Communities Act (Chapter 40A, Section 3A), signed by Governor Baker in January 2021. It requires all 177 MBTA-served communities to zone at least 50 acres within a half mile of an MBTA station for multi-family housing at at least 15 units per acre, permitted as-of-right — no special permits, no discretionary review.

The scope is wide: 51 rapid-transit communities, more than 80 commuter-rail communities, and adjacent towns all fall under the law. According to the Massachusetts Executive Office of Housing and Livable Communities, the theoretical unlock is more than 200,000 units, with a realistic near-term estimate of 50,000 to 80,000.

When Milton Said No

In February 2024, the town of Milton voted roughly 54 to 46 percent against compliance in a referendum. Attorney General Andrea Campbell filed the state's first-ever enforcement lawsuit in April 2024, and Governor Healey simultaneously withheld state discretionary grants, including Local Capital Projects Fund money — making Milton the first community to lose state funding for saying no. Milton passed revised zoning later that year under combined legal and financial pressure, and the courts upheld the Act. The message to other holdouts was unmistakable.

The Affordability Gap

The law has one glaring omission: it includes no built-in affordability requirements. Cities must zone for density, but the resulting units can be entirely market-rate — a design choice that has drawn sharp criticism from housing advocates and set up a predictable second-round fight over inclusionary rules.

Colorado's HB23-1255: The Most Explicit Density Mandate

Signed by Governor Polis in June 2023, Colorado's HB23-1255 goes further than any other state on numeric density. Within a quarter mile of a rail or BRT station, municipalities must allow at least 40 units per acre. Within a half mile, they must allow at least 15 units per acre. According to the Colorado Department of Local Affairs, the law preempts local zoning outright, and communities had until mid-2024 to comply.

The affected geography is essentially the entire RTD station network: Aurora, Lakewood, Englewood, Westminster, Thornton, Arvada, and the rest of the metro Denver ring. Estimated unlock is 30,000 to 50,000 additional units in RTD corridors — many of them at stations that today are still surrounded by surface parking. As with Massachusetts, there is no affordability mandate, which is already generating pushback from local housing coalitions.

Washington State: Stacked Bills, Sound Transit Timing

Washington took a two-bill approach in 2023. HB 1110 requires cities of 75,000 or more to allow fourplexes near transit, and SB 5466 requires cities to permit buildings of up to six stories within a half mile of frequent transit. The Washington Department of Commerce estimates roughly 40,000 to 70,000 units unlocked near the Sound Transit network.

The timing is not accidental. Sound Transit's East Link (see the 2 Line cross-lake connection) opened in 2024, the Federal Way Link Extension (see the Federal Way Link Extension opening) is now online, and Lynnwood Link added another string of new station areas. Every one of those stations is a candidate for the density the state has now legalized. The Northgate buildout — 24 acres, more than 5,000 planned units around the station that opened in 2021 — is the model the rest of the network is chasing.

California's Layered Approach

California never passed the single sweeping mandate its advocates wanted. SB 50, which would have required 4- to 8-story housing within a half mile of rail, died in 2019–2020 under suburban opposition. Instead, the state has stacked roughly ten interlocking bills that together deregulate housing near transit almost as thoroughly.

• AB 2097 (2022): Bans parking minimums within a half mile of any major transit stop with 15-minute frequency. Statewide preemption. According to the UCLA Lewis Center for Regional Policy Studies, the reform potentially unlocks 100,000-plus units through parking reform alone.
• AB 2011 (2022): Housing by-right on commercial land near transit corridors, with a 15 percent affordability mandate baked in.
• AB 1287 (2023): Doubles density bonuses for TOD projects that include affordable units.
• SB 10 (2021): Allows — but doesn't require — cities to upzone near transit to 10 units by-right, with CEQA exemption. Uptake has been limited.

The result is a de facto TOD regime without a single headline law. AB 2097 in particular has been quietly transformative, because it removes the parking cost line that killed so many mid-size infill projects.

New York: The Failure Case

New York remains one of the only major transit-rich states without a statewide TOD mandate. Governor Hochul's Housing Compact, announced in January 2023, would have required LIRR and Metro-North suburbs within a half mile of stations to allow 50 units per acre, plus 3 percent mandatory housing growth targets for downstate suburbs. The administration estimated 250,000 units statewide.

Suburban Democrats from Long Island and Westchester killed it in the spring 2023 budget. What passed instead was tax incentives and density bonuses — no mandate. NYC's own City of Yes for Housing Opportunity (2024) rezoned within city limits with transit bonuses, but the suburbs remain untouched. New Jersey's Transit Village Program, running since 1999, is a voluntary incentive with roughly 35 designated communities as of 2024 — and a useful object lesson in the limits of the carrot without the stick.

Ridership, Case Studies, and the Equity Question

The evidence that TOD actually delivers riders is now decades deep. Arlington, Virginia's Rosslyn-Ballston corridor remains the American gold standard: more than 30,000 workers within a quarter mile of each Metro station, and Arlington generates more tax revenue per square mile than any other Virginia jurisdiction. Denver's RTD counted 40,000-plus TOD units built or planned by 2023, anchored by the 2014 Union Station redevelopment. Portland's MAX has drawn $10.5 billion in TOD investment since 1986. Dallas DART cleared $11 billion by 2018. Atlanta's MARTA, historically auto-oriented, has been catching up since 2016 and is layering explicit TOD requirements into its new Rapid A-Line BRT.

Arthur Nelson at the University of Utah estimates that market demand for walkable TOD housing already exceeds supply by 3 to 4 times in most US metros, and that filling that gap could raise national transit ridership by 20 to 30 percent. The Victoria Transport Policy Institute puts the associated VMT reduction at 20 to 40 percent.

Green Gentrification Is Real

The Urban Displacement Project at UC Berkeley has documented that TOD in low-income communities of color is associated with higher displacement risk — "green gentrification." New market-rate TOD in Seattle, Denver, and Portland typically prices 15 to 30 percent above citywide medians. The state laws in Massachusetts, Colorado, and Washington include no affordability requirements. California's approach is only partial, working through the density bonus law. NJ Transit's own agency-land TOD strategy (see the Red Bank TOD story) is one attempt at a more equitable model, using community land trusts, right-to-return policies, inclusionary zoning, and anti-displacement covenants. The ITDP TOD Standard explicitly penalizes displacement risk in its 8-dimension rating framework.

The Federal Layer

The IIJA includes $1 billion in TOD planning grants over five years, and the FTA's Capital Investment Grant program — New Starts and Small Starts — rewards local land-use policies that support TOD. The stalled BUILD America 250 Act would expand those programs further.

The Numbers at a Glance

What to Watch Next

The next 24 months will test whether these mandates actually produce buildings. Massachusetts is now the enforcement laboratory: the Milton precedent gives the AG a working playbook, but dozens of communities are watching to see whether the state has the political stamina to use it repeatedly. Colorado's mid-2024 compliance deadline has passed, and the interesting question is which RTD stations see actual permit applications rather than nominal rezoning. In Washington, the intersection of new density rules with a Sound Transit network still under expansion may produce the fastest visible change. California's parking reform under AB 2097 will show up first in project pro formas, not headlines — watch for infill approvals in cities that quietly stopped fighting them. And in New York, the question is whether a second push in Albany can crack the suburban veto that killed the Housing Compact. The zoning-transit mismatch took 70 years to build. Undoing it will take more than one legislative session — but for the first time in a generation, the direction is unmistakable.