Pave it when, and if, you need it
One way to reduce paved surfaces while addressing uncertainty about parking demand is to require or allow new developments to pave a reduced number of parking spaces, but hold sufficient land in reserve to provide the additional spaces that might be required. As long as the additional parking is not needed, the land can be landscaped or used to provide other valuable amenities such as a playground or park. This approach, sometimes called a parking reserve or landscaped reserve and sometimes referred to as land banking, has several advantages. First, it allays community concerns about the site being able to provide adequate parking. Second, it defers or foregoes entirely the fiscal and environmental costs of building a portion of the required parking. Third, it highlights the tradeoffs between parking and other amenities, such as open space. This can build a constituency of site users and abutters that prefers to keep the land un-paved, and may be willing to take measures to reduce parking demand rather than increase the supply by losing the open space.
Parking reserves can be especially useful for phased developments, where parking demand may grow in stages as the different components of the project come on-line, and for uses where parking demand is uncertain due to unusual operating characteristics or a lack of data. It can also be a valuable tool for fine-tuning parking provisions in water resources protection areas where runoff from excess paved areas may be a special concern. Land banking for parking can be part of a package that allows reduced parking requirements at employment sites in return for Transportation Demand Management (TDM)measures, so that if the employer falls out of compliance with the agreed-upon TDM plan, they may be required to go to the expense of constructing additional parking. Parking reserves are most appropriate for sites in low- to moderate-density areas where land is not a premium and parking is provided in surface lots, and are not recommended for downtown or other higher density districts as they still reduce the potential density of development.
- The City of Marlborough allows the use of temporary parking reserves in cases where there will be a reduced parking demand for at least a year, such as with a large phased development. Reductions of up to 50% of the requirement are allowed subject to Site Plan approval.
- In the Town of Dennis, the Planning Board may allow applicants to designate a number of parking spaces as a reserve area that can be converted to parking if needed. No limits are specified in the ordinance as to the maximum reduction allowable, but the applicant must be able to justify the reduction in parking.
- Several communities have similar regulations allowing parking spaces to be held in reserve, with variations on how the reduction may be authorized, what type of development review is necessary, and the maximum reduction allowed. These are summarized below.
|Community||Authorizing Body||Type of Review||Maximum Reduction||By-Law Reference|
|Action||Board of Selectmen||Site Plan Special Permit||75%||Section 10.4.4|
|Sudbury||Board of Selectmen||Special Permit||30%||Article 3113|
|Northborough||Board of Selectmen||Site Plan Special Permit||30%||Section 7-20-040, L (5)|
|Cohasset||Planning Board||Site Plan Review||33%||Section 7.2 (10)|
|Tewksbury||Planning Board||Site Plan Special Permit||30%||Section 9481|
- Many cities across the country use landscaped reserves, including Portland (OR), Palo Alto (CA), Carmel (CA), Cleveland (OH), and Iowa City (IA). 
- Palo Alto, California allows reductions of up to 50% of minimum parking requirements when the remainder is held as a landscaped reserve. None of the city’s landscaped reserves have later been required for parking. 
- U.S. Environmental Protection Agency, Parking Spaces / Community Places: Finding the Balance Through Smart Growth Solutions, January 2006; p. 21-22. Available as a free download at http://www.epa.gov/smartgrowth/parking.htm, or click here for the PDF.
- Fitzgerald & Halliday, Inc., Northwest Connecticut Parking Study – Phase II: Model Zoning Regulations for Parking for Northwestern Connecticut, Northwestern Connecticut Council of Governments and Litchfield Hills Council of Elected Officials, September 2003; p. 15. Available as a free download from http://www.fhiplan.com/PDF/NW%20Parking%20Study/NW%20Connecticut%20Parki… or by clicking here.
- Christopher V. Forinash, et al., “Smart Growth Alternatives to Minimum Parking Requirements“, Proceedings from the 2nd Urban Street Symposium, July 28-30, 2003. Available as a free download from http://www.urbanstreet.info/ or click here for the PDF.