Parking: How much is enough?
Many parking lots are unfilled even during peak times, creating unnecessary impervious surfaces.
Can there be such a thing as too much parking? A growing number of cities and towns around the country are answering yes to this question. They are beginning to recognize that too much parking can be as bad as too little and are taking steps to regulate the demand and the supply of parking. Some cities now mandate a parking maximum and not a minimum as is the norm.
Clearly, too much parking wastes land and carries with it a sizable economic penalty, especially in terms of wasted opportunities. But more important, too much parking often saps the vitality of an area by creating large dead zones where people do not want to be. There is also a growing recognition that it is not just the amount of parking that is important. How it is arranged relative to the buildings, who owns it, and how it is operated, are all factors that affect the extent to which parking will have a positive or adverse effect on the surrounding land uses.
To get a better handle on some of these issues, researchers at the University of Connecticut started a two-year-long study in 2003 of parking at six centers around New England. The primary goal was to compare parking at mixed-use, walkable commercial centers to that at centers with more conventional development patterns (control sites).
The results of the analysis show that the mixed-use sites use much less parking, and use the parking more efficiently, than did the control sites. On average, the peak parking use (generally during the holiday shopping period) at the control sites was about 2.3 spaces per 1000 sq. ft. of building square footage. The mixed-use study site required only 1.8 spaces per 1000 sq. ft., or about 24 percent less than the conventional sites.
In terms of efficiency of use, less than 50 percent of the parking spaces at the control sites were filled during the peak shopping period, versus 80 percent occupancy at the mixed-use study sites. In other words, the amount of parking provided at the control sites was more than twice that required even during the peak shopping period. This is a tremendous waste of land and is also environmentally unsound, as it means that a significant amount of unnecessary impervious surface is found at these developments.
The study sites have a few advantages that allow them to operate smoothly at a much higher occupancy level. One important difference is that the study sites have paid municipal lots and garages that serve the whole center and not individual businesses. This consolidation of parking affords a great deal of efficiency. In contrast, most people at the conventional sites drive from one business to another at the center and thus end up using multiple parking spaces for each visit.
There are a number of reasons why the mixed-use sites are "park once" districts. For one, the act of paying for parking cut down on the tendency to move the car once a person is in the district. These mixed-use districts are also much easier to walk in and provide a more pleasant and more interesting environment.
Based on this study, the researchers suggest the following strategies for reducing the negative impact of parking:
- Reduce Minimum Parking Requirements: Most towns could significantly reduce the minimum parking requirements without any noticeable adverse effect.
- Encourage Connected, Mixed-Use Development: The study suggests that mixed-use centers use fewer parking spaces and use the parking provided much more efficiently.
- Re-instigate On-street Parking: On-street parking is the most valued by customers and often the most convenient. It cuts down on the size of the off-street lot that is needed, thus reducing the amount of impervious surface. On-street parking brings other benefits in that it serves a traffic calming function, making a town center feel safer to pedestrians and more like a real center to drivers and pedestrians alike.
- Consider Shared Municipal Lots: Lots shared by different types of businesses are used much more efficiently and do not have as many hours where they sit empty. In addition, consolidated municipal parking promotes a "park once" mindset, which benefits all the businesses in a center. Finally, the parking revenue from municipal parking systems can be used to landscape, beautify, and maintain the streets and other public realms of the center.
The current system of oversupplying parking appears to be wasteful of land and resources, is environmentally unsound, and dampens the economic and social vitality of commercial centers. The good news is that relatively small changes can go a long way in reducing the amount of resources that are devoted to parking and in creating more vibrant centers in our cities and towns.
(Written by Norman W. Garrick, Connecticut Transportation Institute, University of Connecticut, and Wesley E. Marshall, Civil and Environmental Engineering, University of Connecticut, wesley.marshall@uconn.edu.
Reprinted and condensed with permission from Technology Transfer Newsletter, Volume 22, Number 4 — December 2005, Connecticut Transportation Institute's Technology Transfer Center, University of Connecticut, School of Engineering. Read the full article at www.t2center.uconn.edu/tt_newsletters.html.)