Abstract
In U.S. law, states can override actions of local governments that contravene state interests. In practice, preemptions are often more ambiguous nudges, and local responses can vary by interpretation and interests. This paper explores one such case of state preemption: California's 2022 law that limited local governments’ ability to require automobile parking. We find that the law's complexity and ambiguity created intense debates about interpretations, in all jurisdictions, leading to heterogeneous implementation across cities. Local interests also motivated strategic responses to the law, which we present in a threefold taxonomy: cities interested in parking reform used it as a springboard; cities interested in parking reform but facing local resistance used it as a protective shield; recalcitrant cities treated it as an obstacle or subverted the law. Our analysis shows that preemption is not as clear cut as it seems, and what conditions help and hinder changes in actual outcomes.
Introduction
In U.S. law, local governments exist at the pleasure of their states. Indeed, on paper the power of states over localities is almost limitless. It is within a state government's purview to sanction, replace, or even abolish a local government should it deem such action necessary. In principle, then, if local governments act in ways that undermine a state's interests, that state should be able and willing to preempt the local governments—to pass laws that override the offending local actions.
In practice, however, state preemption is less common and more complicated than theory might predict. State officials often hesitate to override localities, and in those instances where a state does move to preempt, the result is less a decisive assertion of authority and more a diluted and ambiguous nudge. This paper explores one such case of preemption: California's 2022 law that limited local governments’ ability to require automobile parking.
Land use regulation, and particularly parking requirements, offer a useful window into preemption, because it represents a situation where local and state interests often collide. States with growing economies, like California, are often interested in encouraging housing (to make it more affordable) and discouraging driving (to control traffic congestion and air pollution). Laws that require car parking with land developments are thus contrary to the state's interests. Individual local governments, though, face different incentives. Their incumbent residents may prefer less housing and abundant parking, especially if the costs of that parking are borne by newcomers. If city officials respond to the preferences of these residents, a collective action problem will result. Each city, by pursuing the course of action it sees as best for itself, will make the state overall worse off. Arguably this is what occurs when every city requires ample parking with every new development (Shoup 2005).
In theory, preemption could offer a clean solution to this problem. The state could simply prohibit local governments from requiring off-street parking, and local governments would abide by that decision. But the reality is more complicated, for two related reasons. First, state governments are not fully insulated from local political pressure, so preemption laws are rarely clean cut. They often include exceptions and carve outs to ensure their passage, which make the bills more confusing and less forceful than a textbook version of preemption might suggest. Consider a 2021 bill that ostensibly ended single-family zoning in California. In an early draft, the bill did exactly that, allowing up to four units on any single-family lot. But requirements were added during the legislative process—including one saying the developer must live in one of the finished units for at least three years—that rendered the bill much harder to use (Ward 2023).
The second point is that state preemption of local land use policy faces a principal-agent problem in ways that many other forms of preemption do not (Monkkonen et al. 2023). Cities are responsible for development approvals, and a city that opposes a state's preemption has many ways to evade it: it can debate the law's ambiguities, or subtly suggest to developers that approval will be easier if they follow the city's original requirement. Such actions may be inappropriate or even illegal, but local actions and developers’ intentions are hard to monitor, and identifying a locality's compliance with a preemption law becomes especially difficult when the law has provisions that let localities plausibly (and in some cases, legally) ignore it.
To put all this another way, the authority to preempt is a function of constitutional design, but the effectiveness of preemption is often a matter of compatible incentives. Are the goals of the people implementing the law the same as those who wrote it? Often they aren’t; otherwise, the preemption would be unnecessary. But the distance between the goals of the preempting and preempted parties matters, as does the amount of wiggle room granted to the preempted parties. With sufficient distance and wiggle room, the effect of the law becomes more varied and unpredictable, as the different parties interpret and act on it in different ways.
These varying interpretations are what we document in this article. It is too early, at the time of this writing, to determine how effective California's parking preemption law ultimately will be. Our purpose instead is to demonstrate that the law's embedded ambiguity, combined with the pre-existing complexity of land use regulation, has already triggered reactions among local governments that suggest its outcomes will be anything but straightforward.
To be clear, our contribution is about how preemption actually works in practice. As we discuss below, much of the existing literature on state preemption focuses on the nature, and sometimes the motive, of the state's preemptive action. Relatively less work examines the question of how those legislative actions translate into policy. California's experience with parking requirements offers us a window into that process. We do not claim that parking reform in California—or parking reform anywhere—will be representative of every attempt at state preemption. Our contribution instead is more modest but still useful: we demonstrate, as existing theory suggests, that land use preemption is by its nature vulnerable to evasion and strategic actions.
In the next section, we review some theory and empirics about preemption. From there we discuss minimum parking requirements, parking reform broadly, and California's preemption law specifically. We then introduce our case study of preemption and discuss our findings about how jurisdictions respond to the state law. The law's complexity and ambiguity created a round of intense debate about how exactly to interpret it, both in cities that support it and in cities that were opposed. Our case study cities developed different stances toward the law, which we present in a threefold taxonomy: Cities where leaders and constituents were interested in parking reform used it as a springboard; cities that had experimented with parking reform but faced resistance from constituents used the state law as a protective shield; and cities where leadership was opposed to state intervention with parking viewed it as an obstacle to navigate or evade.
State Preemption of Local Policy
The most prominent examples of state-level preemption have a political tone: conservative legislatures attempt to thwart the actions of progressive localities, and researchers critique those legislative actions for both undermining progressive outcomes and disrupting the process of local experimentation that federalism allows (Briffault 2018; Fowler and Witt 2019; Hicks et al. 2018; Riverstone-Newell 2017; Schragger 2017). Typically, state legislatures dominated by rural interests pass laws preventing cities from adopting progressive policies—e.g., local minimum wages, local restrictions on gun ownership, and local sanctuary policies for undocumented immigrants (e.g., Fowler and Witt 2019; Goodman, Hatch and McDonald 2021). Empirically, the strongest determinant of this “maximum preemption” is the share of Republicans in the state legislature, and these legislatures target statutes that exist only in the bigger, more-progressive cities of those states (Fowler and Witt 2019).
State preemption of local land use resembles this new preemption in some ways, but differs in others. Laws that prevent the use of certain development restrictions are arguably of the same family as laws that preclude local minimum wages or gun control laws. But land use preemption often attacks regulations used and favored by a majority of localities—not a few progressive dots on the maps of otherwise conservative states—and it is not obvious that the existing local land use regulations are progressive, or that the people writing the preemption statutes are conservative. State-level land use preemptions are often designed to resolve a collective action problem as much as impose policy preferences on localities.
For example, high housing prices tend to be more severe in liberal states dominated by liberal politicians (Kahn 2011; Manville 2023), and the regulations often identified as culprits in the lack of affordability (parking requirements, single-family zoning, large minimum lot sizes) are commonplace. If anything, these regulations are less common in big cities than other parts of the state. So the standard analysis—of a partisan majority placing limits on the policy experiments of its minority rivals—is in this case incomplete. In the twenty-first century United States, it is abolishing single-family zoning, not protecting it, that counts as a policy experiment. 1
Scholarship is largely silent on the impacts of state-level land use preemptions. However, theory implies that the efficacy of a preemption effort will turn on two factors: the incentives of the people being preempted, and the complexity of the process being regulated. If a piece of legislation is functioning mainly as a coordination mechanism, and delivering on outcomes most people want, or at least do not oppose, and if adherence to the law is easy to observe, preemption can be straightforward (Consider, for example, the national law stating that all driving must occur on the right side of the road). If, in contrast, the preemption is designed to force an outcome many people are antagonistic toward, and the outcome is difficult to monitor, the preemption law can more easily be avoided or subverted.
A priori, state preemption of land use probably looks more like the latter situation. Cities often prefer less development to more, and they have many points of contact with developers—most of them unobserved by state regulators—during an approval process (Manville and Osman 2017; Millard-Ball 2021). Compliance with state preemption, therefore, is hard to monitor. In the case of a law that preempted parking regulations, state regulators could try to monitor compliance by tracking the amount of on-site parking constructed with development projects, but these numbers alone tell an incomplete story. Regulators cannot easily know if the developer would have preferred to provide a different number of spaces but for subtle pressure from local officials.
State regulators looking for compliance with the letter of a parking preemption bill may not be able to track compliance with its spirit. Parking requirements make dense development difficult. If one goal of parking preemption is to make development easier (rather than just have fewer parking spaces), cities can undermine the bill by turning to other anti-development tactics. Regulation is often a hydra; efforts to remove one regulation may prompt two more (Monkkonen and Manville 2020). A locality chafed by parking requirements getting rolled back might place stricter limitations on other facets of development—it may limit building height, or expand its minimum lot size. In some ways, the challenge faced by states trying to preempt land use restrictions bears less resemblance to the standard analysis of preemption, and more resemblance to a stream of scholarship in the political economy of law. This scholarship examines how governments can regulate or reduce practices that—like local development restrictions—have high social costs but nevertheless enjoy broad support. The efficacy of such efforts relies on changing established institutions (that is, norms and practices). That change depends in part on whether institutions arise primarily from rules or equilibria (Greif and Kingston 2011). The former case is simpler: if institutions arise from rules, then a government that wishes to change established conditions can design a rule and then enforce it aggressively. The latter is more complicated but perhaps more realistic: institutional change arises organically, following rather than instilling a change in norms.
When rules arise from equilibria, enforcement becomes endogenous to the rule design, rather than separate. The costs of change are smaller, because conflict is a cost, and rules that follow norms will involve lower levels of conflict. The costs of the status quo, however, can be larger, because letting rules wait for norms means that harmful institutions may persist longer. This “sticky norms” problem can be an obstacle to effective preemption (Kahan 2000). If an institution is socially harmful but largely approved of, a state must balance the costs of aggressive enforcement (which may or may not be feasible) against the costs of maintaining the institution. Faced with this choice, the state may split the difference, and pass a law that signals disapproval but that nevertheless, in design or in practice, leaves sufficient ambiguity to limit conflict and allow the undesired activity to continue (Matland 1995). Reform might thus proceed, but more slowly and unevenly than the passage of the law might suggest.
In the case of land use preemption, some localities will be more open to the spirit of the law than others, and their response may vary accordingly (e.g., Wielga 2025). In places where local officials are ahead of their constituents on policy innovation, they might deploy the preemption legislation as a shield and use it to deflect blame and criticism while implementing policies they support. In still other places, officials might be emboldened and use the preemption as a springboard: they might draft local ordinances that align with the preemption and even go beyond it, in breadth or scope.
Parking Minimums and State Parking Preemption
The first city to require that new developments provide a minimum number of parking spaces was Columbus, Ohio, in 1923 (Jakle and Sculle 2004). Minimum parking requirements became a ubiquitous part of land use regulation in the following decades, with the rationale of avoiding spillover parking (Shoup 2005, 1997). In some cases, developers would have built the same amount of parking even without the city's requirements. But typically, the requirements are binding, and thus increase the supply of parking beyond what the market would have provided (Gabbe, Pierce and Clowers 2020; Hess and Rehler 2021; Li and Guo 2014; McDonnell, Madar and Been 2011).
Recently, academics have documented a long list of downsides of parking requirements. The additional parking increases the costs of development, reduces housing densities, makes it difficult to adapt and reuse historic buildings, and reduces walkability (Gabbe and Pierce 2017; Manville 2013; Mukhija and Shoup 2006). The additional parking also ensures that parking is invariably free—it drives the market price of parking to zero—which in turn provides an implicit subsidy to driving (Shoup 2005). With its powerful effects on both land use and transportation, parking policy is a “tail that wags two dogs” (Shoup 1999).
Consider a parcel with a one-space-per-unit parking requirement. Suppose the site can legally hold 15 housing units (e.g., through its allowable Floor Area Ratio and density), but is configured such that only 10 parking spaces could fit on the building's first level. The developer can easily build 10 units, but the eleventh unit would require digging an enormously expensive subterranean level, and the marginal cost of five more units could easily exceed the benefit. It is plausible that only 10 units get built, or—if 10 units don’t make the project pencil—that none would be built. The result of the parking requirement would not be 15 new parking spaces; it would be no new housing. It follows that the desired outcome of parking reform would not be (or only be) buildings with less parking, but more buildings, period.
For decades, planners and policy makers largely perpetuated the norm of excessive parking (Shoup 1999). In a few instances, though, when their hand was forced, state governments preempted local parking requirements. The state of Massachusetts established parking freezes for parts of Boston, first when under pressure from the federal EPA to comply with the Clean Air Act in 1976, and again in 1993 as mitigation for the highway expansion project known as the Big Dig (City of Boston 2019). In 1982, under pressure from New York State (which was, like Massachusetts, being pressured by the EPA over the Clean Air Act), New York City not only lowered its parking minimums for part of Manhattan, but also imposed parking maximums (New York City 2011).
More recently, however, local officials have been the driving force behind parking reform, in response to growing evidence about the harms of parking requirements (Shoup 2005) and efforts by transportation and sustainability advocates (Institute for Transportation & Development Policy 2014). Cities as diverse as Anchorage, Buffalo, London, and Mexico City have eliminated parking requirements to achieve a variety of local goals, without any mandate from higher levels of government (Goodykoontz 2022; Hess and Rehler 2021). As of January 2025, the Parking Reform Network had identified 86 cities and counties in the US and Canada that had abolished parking minimums for all land uses in their jurisdiction (Parking Reform Network 2025).
Many of these locally driven parking reforms occurred in California. In 1985, San Francisco removed parking requirements in downtown commercial developments, and rolled out subsequent reforms through the 2000s and 2010s (Livable City 2015; Millard-Ball 2021) until it ultimately removed all minimum parking requirements 2 in 2018 (City and County of San Francisco 2018). In 2017, Los Angeles removed parking requirements near transit in exchange for affordable housing units (City of Los Angeles 2025). San Diego removed parking requirements for multifamily residential developments near transit in 2019, and then for commercial developments near transit in 2022 (City of San Diego 2019, 2025). Sacramento started rolling back its parking requirements in 2012, ultimately eliminating them citywide (City of Sacramento 2023). These local level parking reforms, particularly through their tie of parking reform to transit proximity, became a model for state legislators who pursued statewide parking preemption in 2022.
California's Parking Preemption
California is also where statewide preemption of parking requirements first succeeded when the legislature passed Assembly Bill (AB) 2097 in 2022. AB 2097 largely eliminated parking requirements in areas within a half-mile of public transit (California State Assembly 2022). The goal of AB 2097 was similar to that of previous local-level efforts—spur housing development, reduce housing costs and promote walking, bicycling, and public transit.
In three important ways, however, AB 2097 differed from local-level reforms. First, the bill included an escape hatch: A process by which local governments could continue to apply their local parking requirements. Second, by dint of being a state law, AB 2097 could not be interpreted and implemented by the people who had written it. The state does not approve housing proposals; localities do. Third, the nature of preemption suggests that at least some of the institutions that would implement the law did not share its goals, and might thus be inclined to interpret the law differently than its authors would.
What did California's legislation say, exactly? The core of AB 2097 states: A public agency shall not impose or enforce any minimum automobile parking requirement on a residential, commercial, or other development project if the project is located within one-half mile of public transit. A major transit stop is as defined in Section 21064.3, except that, for purposes of this section, it also includes major transit stops that are included in the applicable regional transportation plan. “Major transit stop” means a site containing any of the following: (a) An existing rail or bus rapid transit station. (b) A ferry terminal served by either a bus or rail transit service. (c) The intersection of two or more major bus routes with a frequency of service interval of 15 min or less during the morning and afternoon peak commute periods.
3
In summary, then: AB 2097 ostensibly prohibits any public agency from imposing minimum automobile parking requirements on new or existing developments that are within a half mile of a major transit stop. Crucially, the transit stop can either currently exist or be a transit stop that is planned in a regional transportation plan (RTP).
That latter provision creates an additional layer of complexity. RTPs are created and adopted by region-scale metropolitan planning organizations (MPOs). Regional transportation planning is notoriously “paradoxical”: MPOs are required by federal law to adopt an RTP, but not required to implement it (Sciara 2020). The MPOs, in fact, have no implementation powers; implementation relies on the actions of local and state governments. AB 2097's provision that hitched local parking reform to RTPs gave teeth to plans and institutions that have traditionally been relatively toothless.
The RTP provision makes AB 2097 more expansive than it might first appear. A parcel currently far from high-quality transit can fall under the law's purview if a planned high-quality transit stop appears in the RTP. Carveouts and exceptions in the legislation, on the other hand, make AB 2097 less expansive than initial impressions might suggest. It does not apply to hotel-type developments. It does not preclude public agencies from enforcing parking requirements with electric vehicle charging equipment. Nor does it eliminate requirements for parking accessible to people with disabilities. 4
Then there is the actual escape hatch. AB 2097 allows local jurisdictions to enforce minimum parking requirements for housing development projects “if the public agency makes written findings, within 30 days of the receipt of a completed application, that not imposing or enforcing minimum automobile parking requirements on the development would have a substantially negative impact, supported by a preponderance of the evidence in the record, on the public agency's ability to meet its share of specified housing needs or existing residential or commercial parking within ½ mile of the housing development.”
Some projects are exempt from this exemption. AB 2097 does not allow use of the escape hatch for housing projects that: (1) set aside at least 20 percent of the units to be deed-restricted affordable, for students, for the elderly, or for people with disabilities; (2) include fewer than 20 units; or (3) receive parking reductions from another law. Otherwise, the exemption criteria are vague—what would a “substantially negative impact” on “specified housing needs” or parking look like? However, the broader point is that the law is convoluted, and provides a way for cities to keep mandating parking subject to some administrative paperwork and procedures.
Given the logic above and the contours of AB 2097, we might expect localities to heterogeneously and strategically react to this new law. The cities whose interests align with the preemption may have already reformed or eliminated parking requirements—as San Francisco and San Diego, amongst others, had done prior to the law's passage in 2022. Cities that preferred to require parking could find grey areas in the law or make use of the escape hatch. Alternatively, we might expect some cities to feel duty bound to implement the state's mandate to some degree. We examine these possibilities empirically in the remainder of this paper.
Methods
We selected six cities in California and interviewed city representatives and developers in each place. We purposively sampled the six cities for a diversity of regions, built environment context, and population size. We also chose cities to ensure variation on two factors: compliance with the state's housing element law, and the number of recent housing permit applications. The former is an indicator of the policy environment around housing in the city – whether a city aims to encourage or restrict new housing. The latter criterion ensures that cities had enough development occurring for AB 2097 to come into play. We measured both with data from HCD. Lastly, all the selected cities have “major transit stops” and are thus subject to AB 2097.
In using this sampling method and these selection criteria, we necessarily move away from a representative sample of California localities. However, as in most qualitative studies, our goal is explanation rather than representation. Specifically, we are interested in exploring the conditions under which California's parking preemption law leads to changes in local land use policy, and the mechanisms that are in play, rather than the frequency with which those conditions occur (George and Bennett 2004, 31). We discuss the generalizability of our findings—both to other cities subject to AB 2097, and to other cases of state-level preemption—in the conclusion.
To maintain the confidentiality of interviewees, we will not name our exact sample of cities. The six cities were drawn from the sampling frame in Table 1. The sample includes cities in five of the six regions listed in Table 1, cities in major metropolitan regions and rural regions, cities that are central to and satellites of metropolitan centers, and cities of every size category. In addition to our six case studies, we draw on media reports and publicly available documents, such as zoning ordinances, from a wider set of cities to provide concrete examples that illustrate our findings.
Sampling Frame of Cities.
Within each city, we selected people to interview who had direct experience interpreting and implementing AB 2097 in their city or firm. Interviewees included city planning staff, public works staff, transportation staff, appointed planning commissioners, city council members, and local developers. City staff were director- and manager-level within their departments, and in multiple cases brought additional colleagues whose duties included AB 2097 implementation. We interviewed at least one city planner and one developer from each city. In three cases, we also interviewed representatives from the public works or transportation department, the planning commission, and the city council. A summary of interviewees by type of organization and case study city is in Table 2.
Interviews by Case.
Additionally, we interviewed staff at state agencies and non-governmental organizations who had been involved with AB 2097 and its implementation. We conducted a total of 25 interviews. A summary of the total number of interviewees by type of organization is in Table 3.
Interview Sample.
The semi-structured interviews asked open-ended questions about a range of policy implementation topics. Topics included evolution of parking requirements in the city, how AB 2097 affects parking requirements in the city, responses to AB 2097 from cities and developers, the policy implementation process, interpretation of the state law, definitions used by the city, as well as any recent development projects that have used (or tried to use) the provisions of AB 2097. We discussed reactions to the law from interested parties, including any areas of agreement or disagreement between local elected officials, city staff, MPOs, state agency staff, the public, and developers. Interviews with developers also included questions about how this law has affected the nature and design of development projects, and its effects on what projects they have considered or would now consider. 5
Interviews lasted between 30 min and three hours. All were conducted by video conference or phone in the summer of 2024. To provide privacy and encourage candor when discussing evolving policy and projects that are political or sensitive in nature, we did not record the interviews but instead took detailed notes. We reviewed the full set of interview notes and coded them for common topics, themes, ideas, and events that emerged from the interview data. The coding process was iterative; when new topics emerged, we checked for their mention in previously-coded interview data.
Responses to State Preemption
AB 2097 does not prescribe how local governments should implement the law, nor provide any resources to help them implement it. Cities’ implementation actions took many forms that depended in part on local interests and technical capacity. Some cities changed their zoning codes to reflect AB 2097. Some created maps of areas near high-quality transit stops, to identify which parcels were subject to AB 2097. Others tapped their MPO for such maps. Others still evaluated development proposals ad hoc. Several approached the state legislature or state housing agency to clarify or complain about the law.
Implementation also varied because cities interpreted the law differently. The statutory language created grey areas around measuring transit frequency, intersections, distances and so on. These grey areas allowed substantial local discretion that created variation among cities, both those friendly and antagonistic to the law.
Further, developers had their own interpretations of the bill text and a range of considerations for how much parking to provide: Expeditious development timelines, project costs, rapport with city officials, appeal to financiers, and market demand for their “assets.” Some developers indicated that eliminating parking requirements would not necessarily change the amount of parking they construct.
That is, the city-by-city and project-by-project implementation of the state preemption has led to heterogeneity in its implementation and outcomes across the state. We illustrate the detail of that heterogeneity with six cities’ implementation of AB 2097.
Debates of Definitions
Nearly everyone we interviewed—planners, developers, state agencies—mentioned the challenge of defining what it meant to be “within one half mile” of a “major transit stop.” Some of this debate was a genuine exchange about technical definitions, and some was heavily influenced by the localities’ strategic position on the preemption.
California statute defines a major transit stop as a rail or bus rapid transit (BRT) station, a ferry terminal served by bus or rail, or “the intersection of two or more major bus routes with a frequency of service interval of 15 min or less during the morning and afternoon peak commute periods” (see the “California’s Parking Preemption” section, above). But our interviewees grappled with the questions of what constitutes an “intersection,” how to quantify frequency, how to define the peak, and how to geographically represent rail stations.
Distance thresholds provide an illustrative example. Agencies differed in their thresholds for what distance between stops creates an “intersection” of bus routes. These decisions tended to be somewhat arbitrary calls made by technical staff. One city defined an intersection with a case-by-case heuristic—can a person reasonably transfer from Route X to Y at a particular location?—rather than with a set distance. MPOs and the state Department of Transportation (Caltrans) report a wide range in their distance thresholds. Caltrans states that bus stops within 50 meters count as an intersection; the Southern California Association of Governments says 500 feet. The Sacramento Area Council of Governments obviates a distance threshold entirely by pinning bus stops to the closest cross streets (e.g., 5th and Broadway) (Caltrans 2025; SACOG 2024; SCAG 2024).
Another issue that arose was the nature of the ferry terminal. AB 2097 makes no distinction about the trip purpose of the typical ferry rider when it states that ferry terminals can qualify as major transit stops. Yet, one MPO excluded a ferry terminal from its AB 2097 map because the ferry serves mostly tourists rather than commuters.
The most unambiguous definition is an existing rail station. Rail stations are easily identified geographically, the law is agnostic to rail service frequency, and while tourist-oriented railways exist, they are less common than tourist-oriented ferries. Regardless, cities still found ways to debate whether particular rail stations fell under the legislative intent of AB 2097. Debate was especially spirited around rail stations in rural areas; some of these stations see only one train a day, and the trains have faraway destinations like Chicago, Seattle, or New Orleans.
In such instances, officials knew that while the rail station in question fell within the letter of AB 2097, they thought it didn’t provide the transit access the legislation envisioned. “We have an Amtrak station that sadly qualifies us for AB 2097,” a planner said. “We technically qualify but we don’t get the benefits of what qualifies us for this bill … We don’t think we should be subject to it.” A planning commissioner, similarly, noted that the infrequency of service makes their local Amtrak station “barely a rail station, but it's a rail station,” to the city's chagrin.
Accepting that rail stations qualify, however, doesn’t eliminate the debate around them. Rail stations can be big and surrounding parcels irregular, and it makes a difference if the half-mile radius is drawn from a single point in the station's center or from its boundaries. Prior state laws have granted zoning relief near transit, so state agencies have weighed in before on questions about how to measure radii. For example, HCD, in a 2021 technical assistance letter about the state density bonus law, argued that a government code requires the law to be “interpreted liberally” to produce more housing than less (HCD 2021). But assistance letters aren’t definitive, and an assistance letter about one law may not be dispositive about another, especially when neither law offers a definition of its own.
In some cities, staff did approach these issues as technical questions, and sought guidance or revisions from state officials or the MPO. For example, one city asked the MPO, which had created the regional map that the city was using, to move the point from the rail platform to the station entryway. In their estimation, the entryway better reflected station access. Other cities, however, used the uncertainty as an opportunity to interpret AB 2097 to their strategic advantage, with the underlying goal of expanding or limiting the scope of state preemption. Some cities drew rail stations as points on a map, with the point being on the station platform, on the tracks, the centroid of the station parcel, or an entryway to the station. In other cases, jurisdictions drew half-mile radius around the entire parcel on which the rail station is situated—represented geospatially as a polygon—making a much larger area fall under the “near transit” designation. Some cities consider any surrounding parking lots as separate from the rail station, such that the parking lot is in the area “near transit.” And one planning director we interviewed suggested that they might subdivide the parcel of a rail station, so that its surrounding parking lots were not legally part of the station, to minimize the area in their city affected by AB 2097.
Bus stops and routes allowed even more local discretion. Public works staff at one city said they used the “most liberal definition of transit frequency” to create the largest possible area that would be subject to AB 2097, following the city's General Plan goals to encourage housing. With that in mind, city staff drew the first maps of areas near existing major transit stops by measuring the cumulative frequency of buses passing through an intersection. That is, this city considered major transit stops to be stops that served multiple routes and saw a bus at least once every 15 minutes during peak hours. It counted bus routes with the same number but going the opposite direction as two discrete routes. This definition, they thought, best reflects the nature of transit access and the flow of people through stops, and thus best reflects the legislative intent of where to eliminate parking requirements.
MPOs, through their RTPs that define “planned transit networks,” are also an agent in carrying out AB 2097. Many cities rely on their MPO to define areas near transit. A planner said that their city's policy is to be “in lockstep” with the MPOs’ definition and methodology, because the MPO is a trusted technical partner, and a necessary one for defining planned transit stops. When the MPO changes the methodology, so does the city. In another city, planners gave their definition and methodology to the MPO and asked them to create the analogous map for the planned transit network. A developer in that region recalled large disagreement between the city, MPO, and the transit agencies about what qualifies as a major transit stop. The MPO, they said, had been looking at the wrong definition in statute and outdated transit schedules, causing “a big mess” in implementation of the law. Elsewhere, a city was “ignoring” their MPO's AB 2097 map because the MPO, the planning director posited, was “misinterpreting the language of the bill” by including planned as well as existing transit stations.
The role of the RTP in a state preemption of local land use authority creates a new political landscape for MPOs and their member jurisdictions. Local planners vary in their opinions about how RTPs now influence their cities’ parking requirements. A planning director alluded to regional planners overstepping their jurisdiction in the context of AB 2097: the MPO's planners “think they should be the planners for everyone,” the city official opined. Elsewhere, a planner thought that the MPO “needs” to take on the role of the agency with AB 2097 implementation power. But across this range of interests was agreement that AB 2097 creates a new point of friction between MPOs and their localities: “I’d be lying to you if I said that superseding local land use control was not a big factor in what bus routes will be called ‘BRT’ in the next regional plan,” a planner said, warning that city officials may fight planned BRT because of its implications for their parking requirements.
City staff and developers brought up many other ambiguities and debates spurred by AB 2097. A non-exhaustive summary of the various interpretations of the provisions of AB 2097 is in Table 4.
Interpretations of AB 2097.
How do developers interpret these definitions? Developers we interviewed said they take a more conservative approach when determining what projects are “near transit.” An infill developer in Northern California said that their company's “main philosophy,” in general and when using AB 2097, is to use “conservative interpretations” of state housing laws. Why? It is “too risky to try to push for the more permissive interpretation” when designing their projects, in case the city disagrees and sends them back to the drawing board. Project delays and the time that cities spend reviewing plans are expensive for developers—as much as $2,000 a day for every $10 million of project costs, by one developer's accounting—and “parking is too central and too big of an issue to take the risk” of using an interpretation that could delay the approval process. Further, developers were more interested in developing projects that would appeal to their market of renters and buyers than in permissions of state law. “If you don’t provide sufficient parking, you won’t be able to lease the apartments to create a stabilized asset. At the end of the day, the owner of the asset is the one who's taking on the risk,” said a developer.
Strategic Responses
Three types of responses became clear from the interviews: cities that use the state preemption as a “springboard” to push parking reform further than state law required, cities that strategically use the state law as a “shield” to defer responsibility to another level of government, and cities that treat the state law as an obstacle to attenuate or get around. We discuss each in turn.
State law as a springboard. Some cities responded to AB 2097 by going beyond the state requirement. Multiple cities clearly articulated their use of AB 2097 as a “springboard.” Sometimes the jump was relatively small. One city, for example, drew its AB 2097 maps to remove parking requirements if any part of the site is within a half mile of a high-quality transit stop. AB 2097 left this measurement unspecified, but the city eschewed a more conservative definition in state planning law that requires that a certain percentage of the parcel and proposed housing units be less than a half mile from a high-quality transit stop (PRC §21155 2009). The city's planning director explained that this is how the city frequently approached state policies that align with local goals: “the city uses state law to go a little further.”
In other cases, the springboard enabled larger policy change. Several cities have responded to AB 2097 by eliminating parking requirements in entire districts or even citywide. One city was in the middle of updating its General Plan when AB 2097 was passed. Nearly half of the city's land area was “near transit” per AB 2097, and city officials thought it would be “weird and hard” to maintain a map of areas near transit for the purpose of requiring parking in the other half, according to a planning commissioner. So—with persistent, enthusiastic, and “loud” advocacy from community advocacy groups—the planning director recalled how “the city essentially said, ‘let's finish the job’” of AB 2097 and eliminated parking minimums citywide in its General Plan. Several cities have further eliminated parking requirements beyond the state's half-mile mark in the post-AB 2097 era: Culver City, Mountain View, Sacramento, and San Jose (City of Sacramento 2025; Culver City 2022; Kamisher 2022; Margaretten 2024).
Such large reforms usually have precedent. These were cases of state law incentivizing city policy, but interviewees also viewed them as stories of successful incrementalism. One city had been making “very incremental” parking reforms for more than a decade prior to AB 2097. The city had eliminated parking requirements in its downtown, then for certain commercial projects. It later eliminated parking minimums near light rail stations, and for ADUs. When the city updated its most recent housing element, it included a program to eliminate parking requirements citywide and explore parking maximums. As planning staff put it, the city's “discussion about parking reform and eliminating parking minimums was already well in the works” when AB 2097 came along, so the state law wasn’t a “big leap.” In fact, the city was “pretty happy about it” when the governor signed AB 2097.
Those incremental reforms, according to interviewees, were essential to garnering support from the community and city council. Parking requirements changed and “they saw the world didn’t end,” city staff noted. The city's incremental changes also gave City Council and the community an opportunity to see new development and enjoy amenities that were possible because of low and eliminated parking requirements: “they can see the positive changes to the city and their district, and those positive outcomes are powerful.” Also crucial in policy reform, a public works director emphasized, was strong management of the city's parking “resources” through pricing, permitting, and data collection. “Parking is very political and very personal,” they said, so data on the city's parking landscape let city staff “negotiate based on facts, which diffuses fear and grandstanding” when political complaints arise. “Good parking policy has been enabled by good management of parking supply, and it helps those policies result in projects that are actually successful,” the director said.
State law as a shield. Another response from cities is strategic use of the state preemption to shield local staff and officials from complaints and blame. This reaction to preemption occurred in cities where the state law aligns with city goals—often, more housing—but where those goals remained controversial. Elected officials and residents support at the plan level but tend to oppose at the project level. It also happened where the state law did not necessarily align with city goals, but did not directly contradict them. In both cases, local officials used AB 2097 to shield themselves from the ire of residents, council members, and developers by deflecting responsibility to the state.
Some cities have gone through extensive processes and adopted plans to increase housing supply and affordability, in part by reducing or eliminating parking requirements. When developers propose housing projects that would actually use those policies, however, residents object. But AB 2097 “gives them cover” to approve those projects, a planning director said: “The city can work toward priorities for the community as a whole, that council adopted, that may not align with individuals’ interests, and city council can blame the state.” Another planner echoed this sentiment: if city councilors or residents come to planning staff with complaints about parking, they can say “it's a state bill, go talk to your state legislator in Sacramento.” Put simply: “the city can’t disobey state law, so the state law gives us cover.”
One city explicitly said that it uses AB 2097—and other new state housing laws—as a “shield” to implement their local plans. “AB 2097 and other pro-housing state legislation is state law that the city can use as a shield at the project level to further its adopted housing goals,” a planner said. A planning director discussed how staff had “inched” the city toward realizing its own housing and parking goals, and to do so is “constantly reminding the council and residents that we have goals about housing and parking, specifically.” The planning director recalled reminding their city council that state laws like AB 2097 exist because of the collective action problem that results from municipalities requiring parking and limiting housing development. State preemptions like AB 2097 exist “because of all the actions this council has taken over the years – and actions of all councils throughout the state—that have stopped housing construction,” they remembered telling their city council.
City staff described how AB 2097 had let developers build projects that better align with city policy goals. In a recent mixed-use project, developers proposed a ground-level parking garage facing a street that the city was trying to activate for pedestrians. The proposed garage contravened the city's active transportation plans, and was obviated by AB 2097, so staff asked developers to replace parking with “something better for the pedestrian interface.” (Ultimately, a café.) In another case where developers proposed more parking than was required, city staff suggested replacing parking spaces with the project's utility boxes. Generally, staff said they remind developers when they are not required to provide parking because of AB 2097, especially if they get concerned about parking in the project analysis phase. The planning director here also commented on the amenities that their city can enjoy because of eliminated parking minimums: We can get better building design when not constrained by parking requirements. We can get a better pedestrian experience—somewhere to actually walk to that's nice and convenient—for the people who will live there and, importantly, for the people who already live in the nearby neighborhoods. They get more neighborhood amenities through this new flexibility with parking minimums.
The “shield” of state law is also being used by some cities in the opposite way. These cities see the law as both a ceiling and a floor for parking reform—i.e., they are willing to implement the law but will go no further, even when challenged on their interpretations or measurements. Developers and planners described some cities strategically abdicating discretion to other levels of government—the state Public Resources Code, MPOs, transit agencies—to lay blame elsewhere as they use “the most restrictive, conservative definition” of which parcels qualify for the preemption, said a developer. This developer disagreed with a city about their parcel's proximity to a train station, arguing that under HCD's definition for other housing laws, the project should qualify for AB 2097. But discussion with the city was, in the developer's words, “summarily ended by the planning director. The city said, ‘We get our maps from the MPO and that's that.’” A city councilor here averred that the city was indeed carrying out the state law as best they could with their limited resources, and relied on the technical prowess of the MPO. Others thought that cities strategically defer, to drag their heels.
State law as an obstacle. A third response to this state preemption is cities treating the new law as an obstacle to navigate and, in some cases, avoid. Some cities in this category saw AB 2097 as a complicated new process, forced on them by the state, that they had to spend time and resources to figure out. Others disagreed in principle with state preemption of land use authority, even if they had no quarrel with the substantive issue of removing parking minimums. Still other cities disagreed with reducing parking requirements, believing that the city needs to require off-street parking because residents “need cars.” And some disagreed on all counts.
Some city representatives voiced frustration that they “got stuck with” AB 2097. In one case, planning staff said that the city has “progressive policy” to increase multimodal travel and build affordable housing, but such policy doesn’t include removing parking requirements. In another case, planning staff said the city is “pretty conservative, but not crazy”—it's “pro-business, pro-development, and pro-neighborhood”—and anticipated scant use of AB 2097 there. But the city council was “frustrated with the erosion of local control” and opposed AB 2097 as “overreach.” Officials in these cities engaged the state legislature and agencies, seeking clarity and complaining about how the preemption is a bad fit for their community—it's a “one-size-fits-all” approach to policy, they said. “I know everyone always thinks they are unique,” a planner said, but state preemption of land use authority—like AB 2097—“has been a middle finger to cities that aren’t set up to accommodate a bill like this.”
Cities take various tacks to deal with this state-imposed “obstacle.” One city ignored parts of the law: it updated its local plans to reflect AB 2097 near an existing rail station, but not the major transit stops planned in the RTP. Though planned transit is unambiguously included in AB 2097, the planning director thought it too ephemeral: If it was in a plan that has actual funding, then yes—include it. But this route has been in [the MPO's] plans for a really long time. So we ignore their AB 2097 map, and will continue to ignore it until this transit proposal becomes more real.
Some cities are considering new rules or requirements for projects that use AB 2097 to reduce parking supply. In a city with pricing and permit programs for its street parking, a planner said they’d been “aggressive” about withholding parking permits to tenants of developments that don’t supply parking. But the issue hadn’t actually arisen yet—all recent developments had abided by the city's parking requirements. Another city may require transportation demand management plans if developments use AB 2097 to reduce parking. Elsewhere, a developer recalled a city commission talking on the dais about obstructing AB 2097: “One said, on the public record, ‘How do we get around this state law?’” None of the cities interviewed had yet sued the state about AB 2097, or planned to, but one planner said their city “wouldn’t complain if another city filed a lawsuit”—indeed, they would “get behind them.”
Developers who had worked in these cities recalled treacherous pathways to getting their projects entitled and contention around parking even when projects were unambiguously “near transit” per the AB 2097 definition. A developer discussed one of their housing projects, located about 500 feet from a rail station, that had spent nearly a decade in the city's entitlement process, which the developer described as “arbitrary” and replete with “misdirection” and “delay tactics.” The planning department “fought” the developer about the definition of a major transit stop, saying the rail station did not qualify. Several developers described the chilling effect these actions have on housing development: “The numbers speak for themselves—there is essentially no multifamily housing in [this city] because building it is like threading the smallest needle in the world,” in the words of one.
Legally, enforcement of AB 2097 would come from lawsuits filed by developers or HCD against the offending city. Developers said they generally try to work collaboratively with cities, and avoid legal threats, for as long as possible. Lawsuits are costly, both monetarily and in the conflict they create with cities that would ultimately grant their permits, for the current and any future projects. But some developers ultimately brought on legal counsel to advise on state housing and parking laws. “What a difference it has made,” said a developer about hiring land use lawyers, noting a city only seemed to budge from its “culture of ‘no’” when developers involved attorneys. One developer reached out to HCD about a city violating state housing law, which led to the state Attorney General's office putting the city “on notice.” Another city received a letter from a housing watchdog group about violating state housing law—the developer of that project said they heard from the city mayor “within minutes” of the letter being sent. A developer summarized: “The city will quibble with individual developers, but it doesn’t want to be on notice from HCD, the attorney general, or watchdog groups for a systemic problem.”
Discussion and Conclusions
With a single decisive move, state preemption can seemingly sweep aside parochial interests and political obstacles, and impose state will on recalcitrant localities. By the letter of the law, this vision of preemption is not inaccurate. Local governments are creatures of the state, and the state may do with them as they wish. The sword of preemption can cut the Gordian knot of local control, for better or worse.
We show in this paper, however, that while preemption is without question a powerful tool, local governments are rarely powerless in its face. Our particular focus is land use preemption, and our case study is California's parking policy preemption law. This law, while ostensibly prohibiting local governments from requiring parking near public transit, is proving to be less far-reaching than its proponents promised and its opponents feared. Cities that want to continue to impose parking requirements have found numerous ways to do so. They make use of technical ambiguities in the text of the statute, particularly regarding the definition and measurement of “major transit stop,” to limit the scope of the law. They use their soft leverage over developers to encourage them to follow unwritten norms or legally unenforceable zoning provisions over parking. And in principle, they could make use of numerous statutory exemptions, such as parking for electric vehicle charging, to continue to impose parking mandates—although none of our case study cities had resorted to this approach.
Even defying the plain text of the law—for example, by excluding existing ferry terminals or planned transit when identifying the areas subject to AB 2097—has few consequences for cities. A consequence is only likely to arise if a city denies a developer's proposal to supply less parking than the city requires in an area “near transit.” The developer would need to sue the recalcitrant city, but developers said that they are generally reluctant to challenge zoning decisions in the courts. Developers tend to work repeatedly in the same cities, and rely on cooperation of city officials to advance their future projects. Litigation could translate into difficulties for their future projects, if the local government nurses a grudge.
Some cities marginally meddle with or wholly flout the provisions in the law. They believe that the state is making unreasonable decisions about their local context and thus should not be allowed to preempt their local parking requirements. Others are resistant to AB 2097 because of the limitations to their authority—on principle, they object to the state usurping their local land use decisions. While our empirical analysis focuses on a small number of case studies, noncompliance with housing law in California is common and it is reasonable to assume that our results illustrate a more general phenomenon. In 2023 and 2024, for example, over 200 California localities (out of 539) were formally out of compliance with state housing law, in that they had fallen short in at least one of the law's benchmarks (Christopher 2023, Solovieva 2024). More to the point is that the state's housing law has been so rife with loopholes, for so long, that it is an open secret that many cities technically in compliance are actually breaking the rules (Monkkonen, Manville and Friedman 2019, 2023, 2024).
Even if every city fully implemented both the letter and the spirit of AB 2097, the impacts on the ground may still be somewhat modest. The state law preempts parking requirements, not parking itself. Cities concerned with parking supply are often distrustful of developers—they assume developers will “zero park” projects to minimize costs, and all new residents will park a car on the street—and thus fear AB 2097 will create spillover problems. But none of the cities we interviewed described this scenario coming to pass. And in most of California, developers want to provide at least some parking, to increase their returns or because their lenders are reluctant to finance projects with atypical parking ratios. Rather than building housing with dramatically less parking (or none at all), developers use their new flexibility more sparingly, for example by shaving off a few spaces to build on a physically constrained site, or to avoid excavating underground parking. And some shaved off parking spaces only when asked to by the city. To manage parking, developers and cities created shared parking agreements in existing garage or street space, or rental agreements that specified that residents could not own cars. (“Car ownership is not a protected class,” a planning commissioner noted.) AB 2097 is in practice more of a law to reduce barriers to new housing than one to reduce vehicle travel.
Yet it would be a mistake to conclude that this first iteration of parking preemption in California has had no effect. Rules have indeed changed in recalcitrant cities, at least in-form even if not in-use (Ostrom 2009). The larger impacts, however, have been in cities that were favorably predisposed to parking reform in the first place. In some cities, AB 2097 has provided a nudge, moving parking reform up the policy agenda or redefining the default option. Instead of parking requirements being the default and waivers requiring an active policy choice, the lack of parking requirements becomes the policy in the absence of specific action to the contrary. State preemption has also provided a shield, allowing city staff and elected officials to carry out their own reformed parking requirements while deflecting any political blame to state lawmakers. Some cities have even used preemption as a springboard to go further than the state requires, for example, through abolishing parking requirements in the entire city.
Would a more clear-cut state preemption lead to greater policy change among local governments? For example, legislation could require local governments to follow the technical guidance from state agencies (e.g., HCD 2025) that is now simply advisory. Or the state could remove any link to public transit—the source of many of the ambiguities—from the statute and simply prohibit parking requirements altogether. The latter approach would also avoid the incongruity of a preemption being more complex than the regulation that it preempts. Indeed, a central argument against parking requirements is that planners have no special scientific expertise that qualifies them to dictate parking ratios in new development (Shoup 1999). But AB 2097's specification of precise bus frequencies and distances from rail stations perpetuates the idea that planners, rather than individual developers, are best placed to know where parking must be supplied. Moreover, tying the preemption to transit creates a carve-out for communities that do not have transit, and it perpetuates a misunderstanding that parking requirements can only be eliminated in places where transit service meets some threshold. (Our theoretical example of 15 apartments with 10 parking spaces may provide more accessibility and public benefit than no units, regardless of transit.) The link to transit clouds the discourse and makes it understandable that people conflate parking mandates with parking itself.
But it is not clear that a more stringent version of AB 2097 would lead to substantially different outcomes on the ground. First, such a law might not pass the state legislature. Second, there is no clear enforcement mechanism in AB 2097 other than legal action after a city requests more parking for a project near transit. Third, cities would still be able to use their soft power to persuade developers into providing parking.
This third point—the soft power of cities—is a specific example of the principal-agent challenge that bedevils much state preemption. The state (the principal) can relatively easily observe the amount of parking constructed. But it is hard for the state to know if that amount of parking was a choice by the developer or the result of pressure by the city (the agent). Metaphorical arm twisting in a back room—or preemptive avoidance thereof—is fundamentally unobservable. AB 2097 does not require a city to change its zoning code (which can be observed), but even if it did, zoning codes represent de jure rather than de facto parking requirements. Because the state has access to much less information than its city agents, it can only imperfectly enforce its preemption power.
We study a single example of state-level preemption in this paper, that of parking requirements. A natural question, though, is the extent to which the dynamics we identify apply to other policy areas where preemption is common, from school curricula to the availability of library books to bathroom use by transgender people. While our evidence is limited to parking, our analysis points to conditions that help and hinder the effectiveness of a preemption in changing actual outcomes, specifically the alignment of interests between the principals who write legislation and the agents who implement the policy. In cases where those interests are aligned, this preemption is generally working as intended: Cities carry out the law to the best of their understanding, or even increase its extent. The ambiguities of the law create differences of opinion that are seen and treated as a technical matter. Where interests are not aligned between the principals and agents, the preemption is less effective: The ambiguities in the law and opacity of its implementation create a multitude of pathways for cities to drag their heels or subvert the law.
Footnotes
Acknowledgments
The authors extend their gratitude to Professor Donald Shoup for his contributions to the conceptualization and design of this study, as well as for the delight he expressed about its findings, and deeply regret that he passed away before seeing a full draft of this paper.
Ethical Approval
This study received ethical approval from the UCLA IRB (#24-000509) on April 4, 2024.
Informed Consent
UCLA IRB determined that this study was exempt from review. All participants provided written and verbal informed consent prior to participating.
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was made possible with funding received by the University of California Institute of Transportation Studies through the Road Repair and Accountability Act of 2017 (Senate Bill 1). This document is disseminated under the sponsorship of the State of California in the interest of information exchange and does not necessarily reflect the official views or policies of the State of California.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.