The United States is estimated to have anywhere from 722 million to 2 billion parking spaces, and many U.S. cities are commonly associated with car-centric land use and plentiful parking. Houston, Texas is estimated to have over 30 parking spaces per resident, while over 14  percent of Los Angeles County’s land is estimated to consist of parking (3.3 spots per car). Over the past two decades, research from economists has brought parking policy to the forefront of transportation discussions and raised awareness of the impact of cheap, plentiful parking on mobility and housing affordability. In the past several months, Houston, Austin, San Diego, and Los Angeles have taken up parking reform efforts that could mark a departure from the status quo.

Existing and expanded parking minimum exemption zone in Houston. Source: Houston Planning and Development Department

On July 17, the Houston City Council voted to extend its existing parking minimum exemptions beyond the Central Business District and into the adjacent East Downtown area and portions of the Midtown neighborhood, citing high transit ridership, nearby METRORail lines, and a plethora of existing surface and garage parking. The city’s existing parking requirements include, for example, 1.33 spaces for each one-bedroom apartment and 1.66 spaces for every two-bedroom apartment.

Some 150 miles away, the Austin City Council voted on May 2019 to consider eliminating parking requirements within a quarter-mile of major transit corridors and activity centers as part of the city’s land-use code rewrite. Additionally, the Council requested staff to develop a range of possible incentives to boost transit ridership and reduce single-occupancy vehicle trips in December 2018 and was presented with six transportation demand management options earlier last month. Notable among the six options, which include a transit rewards program and free or discounted transit passes to employees, was a recommendation to “unbundle” parking citywide, requiring parking spaces to be leased or sold separately from apartment, condo, or office units.

Outside of Texas, the Los Angeles Planning Department released a draft of its Downtown Community Plan last month, which lays out a range of planning goals and proposed zoning strategies for Downtown. Among the action items to incentivize more affordable housing is a proposal to both unbundle residential parking and eliminate residential parking minimums in Downtown LA.

Los Angeles County also released a sweeping sustainability plan last week that sets ambitious public health, land use, and transportation goals, including reducing per capita vehicle miles traveled (VMT) from 22 miles today to 10 miles by 2045, and increasing the share of trips taken by public transit, micromobility, biking, or walking from 11  percent today to 50  percent in 2045. Among the dozens of proposed action items to meet these targets is a proposal to develop a comprehensive parking reform strategy that includes, but is not limited to:

• Eliminating minimum parking requirements for all new residential units
• Setting parking maximums within half a mile of high-quality transit stops
• Creating and expanding parking benefit districts
• Incentivizing developers to provide less than the maximum allowable parking

In March 2019, San Diego similarly eliminated parking minimums and required parking unbundling for all new residential developments within a half-mile of transit hubs and set a maximum of one parking space per unit for new projects downtown.

Houston, Los Angeles, San Diego, and Austin join regions like Seattle, Miami, Buffalo, and Arlington County, Virginia, among many others, in considering or implementing parking reform initiatives. Parking reform, particularly parking unbundling, has proven to be a highly effective transportation demand management (TDM) strategy to influence travel behaviors and make residents more aware of the true cost of parking. As Donald Shoup writes in The High Cost of Free Parking:

 “Bundled parking hides the cost of owning and using cars, and it distorts choices toward cars and sprawl… By contrast, unbundled parking will reveal the cost of parking, reduce the prices of everything else, and give everyone the option to save money by conserving on cars and driving.”

A study of residential TDM programs in Arlington County, Virginia, where new developments are required to implement TDM measures and transportation performance monitoring as a condition of their permit, found that car ownership rates per resident were 13  percent lower when parking was unbundled, while single-occupancy vehicle (SOV) use was 12.5 percent higher for commute trips and 40 percent higher for non-commute trips when parking was bundled. Other studies have found that households with bundled parking are 50-75  percent less likely to be vehicle-free, even when controlling for potential self-selection effects (i.e. drivers choosing to live in units where parking is bundled).

In addition to reducing car ownership and SOV trips, unbundling parking can also make housing more affordable. Various analyses have measured the effect of parking spots on rent, with one estimate pegging the average construction cost of one parking spot at $18,000, translating to a $225 increase in rent costs. Another estimate sets the price of garage parking at $1,700 a year, or 17 percent of a unit’s rent.

In Miami-Fort Lauderdale and Portland, elimination of parking minimums in certain neighborhoods resulted in parking ratios dropping from 2.53 to 1.69 and 1.50 to 0.90, respectively from 2006 to 2016. Similarly, Seattle’s relaxing of parking requirements downtown and in neighborhoods near high-frequency transit over the past decade saw the number of parking spaces per unit in new apartments plummet from 1.57 in 2004 to 0.63 in 2017. Even with these overall declines, a 2015 study by King County Metro still found that multifamily buildings in the Seattle region supplied over 40 percent more parking than was actually utilized.

Last year, Seattle passed a package of further parking reforms that require parking unbundling in new and existing buildings of 10 units or more as well as new commercial leases for new and existing structures that are 10,000 square feet or greater. This package also creates flexible-use parking designations to make it easier for property owners to lease/share unused parking spaces to those outside the building, allows for park-and-ride facilities within garages in certain areas, and expands the number of neighborhoods exempt from parking requirements by clarifying the definition of “frequent transit service.”

The wave of cities taking up parking reform in 2019 suggests that more policymakers are reevaluating traditional approaches to parking for a variety of reasons. As Houston monitors the results of its expanded market-priced parking program and both Los Angeles and Austin consider wide-scale parking minimum reduction and unbundling, these regions ought to take note of the results of parking reform efforts in places like Seattle, Miami, and Arlington, VA.

(Ed. Note: The Eno Center has done a lot of work on parking over the last 98 years, much of it from the prevailing point of view of traffic engineers at the time – from this piece in 1950 bemoaning the lack of parking in downtown business districts all the way to this piece in 1997 explaining how ISTEA worked parking into transportation planning. Go to www.enotrans.org/quarterly/ for a full index of articles published in Eno’s Traffic Quarterly and Transportation Quarterly from 1947 to 2003.)