Executive Summary
This research investigates the rationale behind the parking mandate in the minimum street width requirement for residential streets adopted by most local U.S. governments. For example, a minimum width requirement of 36 feet for a residential street automatically provides two 10-foot traffic lanes and two 8-foot parking lanes, making it a de facto parking policy. Such a street standard provides a large amount (between 740 million and 1.5 billion) of parking spaces on residential streets, in addition to abundant off-street parking spaces (garage and driveway), and it costs trillions of dollars in road investments. This research explores the two common beliefs underlying the parking mandate: that it is an amenity reflecting market demand, and that it is a technical necessity based on traffic safety concerns.
This research surveyed the decision makers of street standards in the United States: directors of departments of public works or transportation in local governments. It targeted the 283 cities with populations over 50,000 from the most populous 52 metropolitan areas in the United States. Decision makers in these cities were asked 36 questions in the following four categories: rationale for the minimum street width requirement, rationale for the parking mandate, the double standard between private and public streets, and the construction and maintenance costs of streets. Ninety-seven cities (34 percent) completed this survey. In addition, 11 developers and representatives from 9 homeowners associations were interviewed to provide supplemental information.
The study found that local decision makers have an inconsistent and ambiguous understanding of the rationale for mandating parking through the minimum street width requirement. Decision makers believe that parking is provided because it is needed by residents and visitors, but in actuality it is provided through the minimum width requirement under the guise of technical necessity. This inconsistency calls into question both the amenity and necessity arguments. In addition, decision makers fail to adequately explain the double standard in parking requirements, in which the minimum width is much narrower for private streets than public streets. Respondents used the same amenity and necessity arguments to explain the requirement differences, which suggests that the parking mandate is likely neither an amenity nor a necessity.
The report suggests two policy reforms. The first is to surface the “submerged” parking mandate by making it a stand-alone policy, so that it no longer hides behind the technical street standards, avoiding public oversight. Street parking should be addressed separately in development regulations with a detailed analysis of both residents’ and visitors’ demand. The minimum width requirement should be based on considerations related to traffic movement and access rather than parking. The second suggested policy reform is to eliminate the double standard between public and private streets and make parking optional for residential streets. These policy initiatives would eliminate excessive parking spaces, mitigate associated externalities, correct market distortions, and avoid shifting risks from local governments to families.