Smart Growth Parking Requirements Review Parking needs for transit-oriented developments (TODs) are different than parking needs for traditional developments. Typical parking standards are set with traditional developments in mind. A study of parking occupancy at TODs in San Diego County and a review of associated TOD parking occupancy literature is reported here. BY Richard Lee, Ph.D., AICP, Robert Rees, P.E., AND Mackenzie Watten, E.I.T. Editor s note: This article uses information from Parking Generation, 3rd Edition (2004). ITE has since released Parking Generation, 4th Edition (2010). At the time of this study, the data from the 4th edition were not available. Smart growth developments typically feature relatively dense land uses, compatible with pedestrian amenities and with good access to public transportation. The diversity of uses within close proximity encourages walking within the site, even if visitors arrive by car, as well as greater usage of public transit than in typical suburban developments. Furthermore, research has shown that vehicle ownership for residents in smart growth developments is lower than other areas (Arrington and Cervero, 2008). These factors suggest that parking demand in smart growth areas should also be lower than elsewhere and that parking supplies should reflect this fact. The U.S. Environmental Protection Agency (EPA) published guidance on parking provisions for smart growth areas. Recognizing connections between mixeduse development, driving, and parking, the EPA, in a publication on parking in smart growth developments, stated [T]ypical parking regulations and codes simply require a set amount of parking for a given square footage or number of units, assuming all trips will be by private automobile and ignoring the neighborhood s particular mix of uses, access to transit and walking, and context within the metropolitan region. Such inflexible parking requirements can force businesses to provide unneeded parking that wastes space and money. [I] nflexible minimum parking requirements are the norm but they represent a barrier to better development. (EPA, 2006). Lower parking supplies can reinforce lower vehicle trip generation, a fundamental goal of smart growth. Donald Shoup (professor of urban planning, University of California, Los Angeles, USA, and a critic of minimum parking requirements) contends that by making parking more scarce and costly, people will become more likely to travel by transit, by bike, or on foot. As parking costs increase (in terms of dollar cost or time cost associated with searching for scarce parking), drivers will reevaluate their mode choice, and some will change travel behavior (Shoup, 2005). This article reviews current parking requirements and policies in the San Diego (California, USA) Association of Governments (SANDAG) region and highlights relevant smart growth parking demand and policy studies. It establishes the reasonableness of lower parking supply rates for smart growth developments and recommends parking rates for specific land use categories. It also delineates auxiliary parking management strategies that can and should complement lower parking rates. EXISTING LOCAL JURISDICTION PARKING REQUIREMENTS Parking supplied for new development is controlled by a jurisdiction s parking code. A review of SANDAG s member jurisdictions codes revealed some special parking requirements and strategies for smart growth developments; SANDAG recently released smart growth design guidelines Designing for Smart Growth, Creating Great Places in the San Diego Region (June 2009) that propose parking policies and design recommendations specifically for smart growth developments. Table 1 summarizes the range of current parking standards within SANDAG jurisdictions. ITE PARKING Generation: Implications for Smart Growth Parking The Institute of Transportation Engineers (ITE) Parking Generation (3rd edition), using a national database of parking studies, summarizes observed parking 36 ITE Journal / December 2010
demand for many land uses. The studies incorporated into the informational report primarily address single-use, suburban development sites where free parking is provided on site. This emphasis likely results in higher parking demand rates than would be anticipated with smart growth development, where non-auto travel modes and shared parking between uses serve to reduce parking demand. (Note that it is common engineering practice to add a 10 percent factor to the estimated demand as a contingency to allow drivers to readily find an available parking space.) Residential Parking Demand Residential units in smart growth developments generally fall within Parking Generation s multi-family residential category. Comparing typical code values (shown in Table 1) against Parking Generation demand values demonstrates that existing parking requirements in the San Diego region generally exceed observed parking demand ratios, often by a substantial amount. Parking Generation makes note of additional research on vehicles owned per household. It reports that for areas within one-third mile of a light rail station and more than 10 miles from the central business district (which describes many SANDAG-designated smart growth developments), the average vehicles owned per household numbered between 1.0 and 1.3, substantially lower than the national average value of 2.0 vehicles per household per the 2000 US Census. Office Parking Demand Parking Generation presents a weekday average peak period parking demand of 2.84 and 2.40 spaces per 1,000 square feet in suburban and urban office locations, respectively, with an overall average demand rate of 2.62. The lowest office parking supply requirement found in the San Diego region was 3.33 spaces per 1,000 square feet, substantially higher than the Parking Generation average rate. Parking Generation also summarizes demand studies in areas with priced parking and high-quality transit options available. Not surprisingly, office parking demand in these areas is substantially lower, with documented parking ratios between 1.00 and 2.00 spaces per 1,000 square feet. Table 1. Parking demand vs. existing San Diego jurisdiction parking requirements. Estimated Parking Demand 1 Retail Parking Demand Retail parking demand varies widely among different types of commercial uses. Parking Generation identifies five shopping center types. The weekday (December) peak parking demand averaged over all five shopping center types is 3.76 spaces per 1,000 square feet, which equates to a calculated parking supply rate of 4.14 (including the 10 percent contingency factor). The shopping centers studied are mainly in suburban, auto-oriented settings. Parking Generation also finds that weekday non-december parking demand is 2.65, requiring a parking supply of 2.92 (including the 10 percent factor). This suggests that if the retail component of smart growth development is not subject to pronounced seasonal peaking (e.g., if the focus of the retail uses is on convenience goods for residents and commuters), retail parking rates in smart growth developments could be substantially lower. In view of the wide variety of demand rates found in Parking Generation, the Urban Land Institute s (ULI) Shared Parking (2nd edition) was examined as a second source. Shared Parking recommends a parking supply of between 3.6 and 4.5 parking spaces per 1,000 square feet of retail uses (defined as shopping center ) to meet peak parking demand in December. Current San Diego parking requirements from Table 1 show a range of 3.3 to 5 spaces per 1,000 square feet, with an average of around 4. These rates are generally consistent with the parking demand rates from the ITE and ULI publications. Current Parking Supply Rates in San Diego Area Urban Suburban Lowest Average Residential Multi-Family 2 1.00 1.20 1.25 1.75 2.50 Office 3 2.40 2.84 3.33 3.60 Retail 3 2.65 3.76 3.30 4.00 Notes: 1. Residential, Office, and Retail rates from ITE Parking Generation (using LUCs 221, 701 and 820) 2. Rate is per dwelling unit 3. Rate is per 1,000 square feet of leasable area Sources: Fehr & Peers, 2009. ITE Parking Generation, 3rd Edition, 2004. OTHER STUDIES OF SMART GROWTH PARKING DEMAND AND POLICIES Cervero et al. (2009) A recent study led by Robert Cervero of the University of California, Berkeley, USA, found that the weighted average of peak parking demand for residential units at transit-oriented developments in the San Francisco Bay Area and Portland, Oregon, USA, was 1.15 spaces per dwelling unit, close to Parking Generation s observed average value of 1.20 spaces per dwelling unit. By contrast, the weighted average parking supply at these sites was 1.57 spaces per dwelling unit, 30 to 35 percent above the observed parking demand (Cervero et al., 2009). Even the highest observed demand is below the typical parking requirement in the San Diego region. Caltrans (2002) A 2002 study by the California Department of Transportation found evidence supporting parking reductions for commercial and office uses in transit-oriented developments. Case studies showed that after parking reductions were negotiated by developers, parking supply was still sufficient. Table 2 summarizes findings from three case studies: Pacific Court, a mixed-use, infill development in urban Long Beach, California, USA, containing 142 apartments and 96,000 square feet of retail and commercial development, served by light rail transit every five to 10 minutes; Pleasant Hill Bay Area Rapid Transit (BART) station area, containing ITE Journal / December 2010 37
Table 2. Transit-oriented development non-residential parking reduction case studies. Transit-Oriented Development 411,000 square feet of office, 40,000 square feet of retail and 350 apartments and townhouses in the suburban San Francisco Bay Area. The site is served by heavy rail every five to 10 minutes during peak hours and every 15 minutes during off-peak hours; and Dadeland South, a development in suburban Miami, Florida, USA, containing 500,000 square feet of office and 605 hotel rooms, served by light rail every five minutes during peak hours and every 15 minutes during off-peak hours, as well as bus service every 10 minutes. PARKING DEMAND AT EXISTING SMART GROWTH SITES IN THE SAN DIEGO REGION The preceding section described studies of smart growth parking demand elsewhere. This section describes smart growth parking demand evidence from the San Diego region. This evidence, though limited, corroborates findings from studies elsewhere. One-day mid-afternoon parking demand counts (occupancy versus supply) were collected by SANDAG staff in September 2009 at several mixed-use sites. Additional counts were collected by Fehr & Peers staff in June 2010, including an evening count at a site with a movie theater. These sites were selected from those studied in validating the region s smart growth trip generation tool. The sites selected have a mixture of land uses, but all have off-street parking that can be accurately counted. The parking counts revealed that the mixed-use developments have a lower Parking Reduction Experience Pacific Court (Long Beach, CA) Retail 60% Parking sufficient but not excessive Pleasant Hill BART (CA) Office 34% Parking sufficient, leasing excess Retail 20% spaces to BART Dadeland South (Miami, FL) Office 38% Excess capacity in office garages Source: California Department of Transportation. Statewide Transit-Oriented Development Study: Parking and TOD: Challenges and Opportunities (Special Report), 2002. parking supply than required for the individual uses under city code, suggesting that shared parking may have been recognized in the planning for these projects. Even so, the developments surveyed tended to be over-parked (i.e., the supply is greater than what is needed on typical weekday). Only one site (La Mesa Village Plaza) had parking occupancy as high as 90 percent. Further study during different seasons would be necessary to fully analyze parking demand at these sites. However, the initial data suggest that applying current parking requirements to these sites would result in a significant oversupply of parking. Table 3 summarizes the expected parking supply using city code, observed parking supply, and observed parking demand at the mixed-use sites surveyed. CONCLUSIONS: Suggested Parking Rates for Smart Growth Developments Residential Multi-Family ITE s Parking Generation (3rd edition) showed weekday average peak parking demand for low/mid-rise apartments to be 1.20 spaces per dwelling unit in suburban locations and 1.00 spaces per unit in urban locations. A study by Robert Cervero at the University of California, Berkeley found a weighted average of peak parking demand at transit-oriented developments of 1.15 spaces per unit. We recommend averaging these three demand analyses for a demand rate of 1.12; adding a 10 percent contingency factor suggests a parking supply rate of 1.25 spaces per dwelling unit. This value represents a reduction from most existing standards, yet conforms to the upper bounds of observed values. Office ITE s Parking Generation (3rd edition) showed weekday average peak parking demand for offices to be between 2.40 and 2.84 vehicles per 1,000 square feet, depending on the location; adding a 10 percent buffer to these rates results in corresponding supply rates of between 2.64 and 3.12 spaces. The 2002 transit-oriented development study by Caltrans cites two case studies where office parking requirements were decreased. The Pleasant Hill BART transit-oriented development negotiated office parking standards of 3.3 spaces per 1,000 square feet and found that there was enough excess parking to allow leasing some spaces to BART patrons. Dadeland South, a transit-oriented development in suburban Miami, Florida, USA, negotiated office parking standards of 2.5 spaces per 1,000 square feet, and excess parking supply has been observed. We recommend averaging these four supply rates to calculate a recommended rate of 2.9 spaces per 1,000 square feet. This value represents a reduction from most existing standards, while conforming to the upper bounds of observed values for office uses in the region. Retail ITE s Parking Generation showed weekday average peak parking demand for retail to be 2.65 and 3.76 spaces per 1,000 square feet in non-december and December, respectively; adding a 10 percent buffer results in corresponding supply rates of 2.92 and 4.14 spaces. ULI s Shared Parking recommends between 3.6 and 4.5 spaces per 1,000 square feet of retail. The 2002 transit-oriented development study by Caltrans noted one case study in which retail parking requirements were decreased to 2.0 spaces per 1,000 square feet, and parking has been sufficient. We conservatively suggest reducing the basic retail parking standards only slightly to 3.60 spaces per 1,000 square feet. We recommend using the ULI Shared Parking methodology to determine the reasonableness of further reductions. Table 4 summarizes the suggested guidance on parking rates for smart growth development. 38 ITE Journal / December 2010
Site Hazard Center Morena Linda Vista Location Table 3. Parking demand at existing San Diego smart growth developments. Size Description Supply per Code San Diego 89,000 square feet Strip Commercial 223 18,000 square feet Sit-Down High Turnover Restaurant 45 2,000 square feet Fast Food Restaurant 5 256,000 square feet Office 845 240 occupied rooms Hotel 240 1540 seats Movie Theater 467 Linda Vista 185 dwelling units Apartments 278 14,000 square feet Sit-Down High Turnover Restaurant 35 3,000 square feet Fast Food Restaurant (Starbucks) 8 8,000 square feet Specialty Retail 20 Transit Station 165 Uptown Hillcrest 311 units Condominiums 467 La Mesa Village Plaza Otay Ranch 67,200 square feet Neighborhood Shopping Center 168 70,000 square feet Supermarket 175 3,000 square feet Government Office 10 La Mesa 14,300 square feet Office 48 Chula Vista 20,200 square feet Sit-Down High Turnover Restaurant 81 2,000 square feet Fast Food Restaurant (Starbucks) 8 8,000 square feet Specialty Retail 32 271 units Apartments 407 8 fueling stations Gas Station with Food Mart 8 67,400 square feet Medical Office 223 38,000 square feet Neighborhood Shopping Center 190 1. Second count at Hazard Center at 7:00 p.m. to account for movie theater use Source: SANDAG, Fehr & Peers, 2009. Observed Supply 1825 1628 506 265 820 464 Occupied Spaces Parking Occupancy (Occupied Spaces vs. Observed Supply) 890 55% 1111 1 68% 170 64% 225 85% 376 81% 394 85% 169 279 252 90% 828 456 273 60% Parking Management Strategies for Smart Growth Developments This article established that current parking requirements in the San Diego region are likely higher than typical parking demand at smart growth developments, and that reduced parking supply rates (Table 4) would be appropriate. Intrinsic smart growth development characteristics such as higher densities, proximity to transit, mixed uses with local-serving retail, and enhanced bicycle/pedestrian facilities can serve to reduce parking demand. In addition, parking management policies and strategies can further enhance parking reductions possible with smart Table 4. Suggested San Diego smart growth development parking supply rates. Estimated Parking Demand 1 Typical Code Requirements San Diego Region Urban Suburban Lowest Average Suggested Rates Reduction From Typical Rates Residential Multi-Family 2 1.00 1.20 1.25 1.75 2.50 1.25 0 50% Office 3 2.40 2.84 3.33 3.60 2.90 12 20% Retail 3 2.65 3.76 3.30 4.00 3.60 0 10% Notes: 1. Residential, Office, and Retail rates from ITE Parking Generation 2. Rate is per dwelling unit 3. Rate is per 1,000 square feet of leasable area Sources: Fehr & Peers, 2009. ITE Parking Generation 3rd Edition, 2004. ITE Journal / December 2010 39
Table 5. Recommended San Diego smart growth development parking strategies. Parking Strategy Potential Parking Reduction Cost to Implement Shared Parking 10 20% growth development; Table 5 highlights some of these supplementary strategies. These strategies can further reduce the number of parking spaces required and play to smart growth development s strength its ability to combine accessibility and convenience through diversified land use and accommodation of all transportation modes. Application for Other Regions While the preceding recommendations were validated with data from the SANDAG region, the underlying research is based on many different regions. For those regions interested in updating parking standards for TODs, we provide the following recommendations: Conduct parking surveys of local smart growth developments in the region on different days of the week and at different times of year to supplement the data in Table 6; Maximize utilization of existing parking in infill smart growth developments by conducting area-wide parking studies and creating parking management districts to determine if parking spaces are available, and if so, make arrangements for infill development to utilize them through lease agreements or other mechanisms; Monitor parking demand at new smart growth developments on a regular basis to establish a regional database of smart growth parking demand and parking demand management effectiveness; and More detailed parking analysis during planning Transit Pass Program 5 20% Developer includes in price of building, overall decrease in cost because of fewer parking spaces Charging for Parking 5 20% Tied to use of parking Unbundled Parking 5 10% Minor administrative costs Car-Sharing 2 5% Developer dedication of parking spaces to car-sharing Source: Fehr & Peers, 2009. Document and then duplicate strategies that prove effective to enhance parking management practices. n References Arrington, G.B. and Cervero, R. Effects of TOD on Housing Parking, and Travel. Washington, DC, 2008. California Department of Transportation. Statewide Transit-Oriented Development Study Parking and TOD: Challenges and Opportunities (Special Report). 2002. Cervero, R., Adkins, A., and Sullivan, C. Are TODs Over-Parked? University of California Transportation Center Research Paper No. 882, 2009. Environmental Protection Agency. Parking Spaces / Community Places Finding the Balance through Smart Growth Solutions. Washington, DC, 2006. Institute of Transportation Engineers. Parking Generation, 3rd edition. Washington, DC, 2004. Metropolitan Transportation Commission. Toolbox/Handbook: Parking Best Practices & Strategies For Supporting Transit Oriented Development in the San Francisco Bay Area. Oakland, CA, 2007. San Diego Association of Governments. Designing for Smart Growth, Creating Great Places in the San Diego Region. San Diego, CA, 2009. San Diego Association of Governments. Parking Strategies for Smart Growth: Planning Tools for the San Diego Region. San Diego, CA, 2010. Shoup, Donald, The High Cost of Free Parking, Chicago: Planners Press, 2005. Urban Land Institute. Shared Parking, 2nd edition. Washington, DC, 2005. Richard Lee, Ph.D., AICP is an associate at Fehr & Peers Transportation Consultants in Walnut Creek, California, USA. He has more than 20 years of experience as a transportation consultant and academic. He has taught transportation planning and led major transportation research projects at several universities, including Massey University in New Zealand, Cal Poly San Luis Obispo, and most recently at San José State University, UC- Berkeley, and UC-Davis. He is currently leading a research project at UC-Davis to develop a tool that practitioners can use to estimate multimodal trip-generation rates for proposed smart growth land use development projects in California. He is a member of ITE. Robert Rees, P.E. is a principal at Fehr & Peers Transportation Consultants in Walnut Creek, California, USA. He is a registered civil engineer and traffic engineer in California and a registered Professional Traffic Operations Engineer (PTOE) with 23 years of experience. He is currently working to redefine performance standards to support multimodal transportation infrastructure investment. He is a member of ITE. Mackenzie Watten, E.I.T. is an engineer at Fehr & Peers Transportation Consultants in Walnut Creek, California, USA. He is a registered Engineer in Training in California. His areas of expertise include smart growth impact analysis, parking studies, and long-range transportation planning. 40 ITE Journal / December 2010