Under the Bloomberg administration, New York City has made a remarkable effort to make itself a more environmentally sustainable and pedestrian-friendly place. However, the city’s zoning policies will erode this progress unless they are changed, according to a new Transportation Alternatives study, Suburbanizing the City.

At issue are zoning regulations which require nearly all new residential developments to include 0.4 to 1 parking spaces per dwelling unit, far more than currently exist in many NYC neighborhoods. For example, Park Slope in Brooklyn has only 0.06 off-street parking spaces per dwelling unit — but most of it is zoned for 0.5 spaces/unit. In other words, if all of the housing in Park Slope was torn down and replaced with new development containing the same number of units, zoning regulations would require the construction of more than eight times as many off-street parking spaces as exists today.

This is a hypothetical situation, but it demonstrates how new development is tilting NYC towards more traffic and congestion. The city projects a need for 265,000 additional dwelling units by 2030. At currently mandated parking requirements, this will translate into a huge increase in the amount of parking in NYC. These “free” spaces act as an incentive for residents to own and use cars, and the report’s authors estimate that residents of new developments will be 42% to 49% more likely to own cars than the average New Yorker. By 2030, the result of new development will be an increase of 1-1.55 billion annual vehicle miles traveled, and an additional 430,000 to 454,000 tons of carbon emissions.

Parking requirements also make homeownership less viable for many New Yorkers because of the “bundling” of accessory parking and housing (where the price of a house, co-op, etc. includes the price of a parking space, making it more expensive than it would otherwise be). Even more counterproductive are parking requirements for affordable housing developments, which force the public to subsidize parking, often in neighborhoods where less than 20% of residents drive.

These are important issues, but according to the report, the city “has no tangible count of on or off-street parking” and “employs no methodology to understand the relationship between parking” and traffic, pollution, emissions, health, or quality of life. Not only are the city’s records of parking garages filled with omissions and inaccuracies, but there is no record of driveways, alley parking, or garages in small residential buildings.

Along with Transportation Alternatives, Tri-State, the Regional Plan Association, the New York League of Conservation Voters, the Pratt Institute for Community Development, Environmental Defense Fund, and others sent the report to Mayor Bloomberg’s office, urging him to implement the report’s recommendations:

1. The city should inventory existing and planned off-street parking, and measure the effects of new parking on traffic and congestion.
2. The city should consider policies which would reduce required parking, including “unbundling” parking and residences, eliminating minimum parking requirements, change minimum parking requirements into maximum parking restrictions, limit curb cuts, link parking requirements to proximity to transit, and incentivize car-sharing.
3. Revise environmental laws, such as NYC’s CEQRA regulation, to fully account for the impact of new parking.
4. End direct subsidy of new parking and freeze the issue of special parking permits in the Manhattan core, at least until an inventory of existing and planned parking is finished. Eliminate minimum parking requirements for affordable housing developments.