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Parking Study 03-23-2011Kimley -Horn and Associates, Inc Memorandum March 23, 2011 ■ Suite aN To: David Cox, AIA 2550Univer4 Avenue West Walmart Stores, Inc. St. Paul, Minnesota 55114 From: Brian Smalkoski, P.E., AICP, PTP, PTOE William Matzek, P.E., CPESC, LEED AP Date: March 23, 2011 Subject: Walmart 5949 -00 Chanhassen, MN INTRODUCTION Walmart Supercenters follow a variety of design variations, typically ranging from approximately 90,000 to 220,000 square feet. At around 120,000 square feet, the proposed Chanhassen Supercenter represents a relatively compact footprint for a discount store that includes a full- service grocery department. Classified as free - standing discount superstores (Land Use 813) by the Institute of Transportation Engineers (ITE), Walmart Supercenters typically utilize independent trip and parking generation rates from the more general free- standing discount store classification (Land Use 815), which do not include full - service grocery departments. Parking Generation, 4`" Edition`, published in 2010 by ITE, includes only a single parking generation study of a discount superstore. Carried out on a Wednesday in mid- April, the observed peak parking demand ratio for the 220,000 square -foot site was found to be 1.85 vehicles per 1,000 square feet gross floor area (GFA). Due to the lack of available data for Saturday parking generation rates at compact discount superstores, it was necessary to conduct counts at local sites in order to establish reasonable parking generation rates for a typical Saturday in December at the proposed Chanhassen, MN Walmart Supercenter. PARKING STUDY A total of three sites located in the Minneapolis -Saint Paul metropolitan area were selected for analysis. Each site, located in Apple Valley, Bloomington, and Eden Prairie, respectively, was originally constructed as a standard Walmart store, and underwent expansion during 2009 -2010 to allow for the inclusion of a full- service grocery department. With an average size of 142,000 square feet, the three sites studied were 118,000, 121,000, and 188,000 square -foot Supercenters, post - expansion. Parking supply at each site was calculated at 5.0, 5.0, and 4.4 spaces per 1,000 square feet GFA, respectively, for a weighted average of 4.7 spaces per 1,000 square feet GFA. Ten hourly independent field counts were ■ TEL 651 645 4197 FAX 651 645 5116 Kimley -Horn and Associates, Inc Average Peak Period Parking Demand vs. 1,000 sq. ft. GFA On a: Saturday (Non- December) conducted on Saturday, February 19, 2011, at each of the three sites between 9:00 a.m. and 7:00 p.m. Although demand never exceeded the effective supply of parking, snow storage reduced the observed February parking supply at each site by 30 %, 32 %, and 10 %, respectively. The peak hour of demand was unique at each site, with the average peak hour falling between 2 and 3 p.m. The final results of the parking study documented Saturday maximum demand ratios of 2.54, 2.83 and 2.37 vehicles per 1,000 square feet GFA. This represents an average ratio of 2.58 vehicles per 1,000 square feet GFA with a standard deviation of 0.23. Final results of the parking study, formatted to represent standard ITE documentation, are provided in Figure 1. Land Use: 813 Free - Standing Discount Superstore Statistic Peak Period Demand Peak Period 1:00 -200 .m; 200 -3:00 .m; 400 -5:00 p.m. Number ofStudy Sites 3 Average Size ofStudy Sites 142000 sq. fl. GFA Averag Peak Period Parking Demand 2.58 vehicles per 1,000 sq. R GFA Standard Deviation 0.23 Coefficient of Variation 9% Range 2.37 -2.83 vehicles per 1,000 sq. ft. GFA 85th Percentile 2.74 vehicles per 1,000 sq. R GFA 33rd Percentile 2.48 vehicles per 1,000 sq. R GFA Saturday Non-December Peak Period Parking Demand 600 500 400 0 300 6 6 1 200 100 0 0 20 40 60 80 100 120 140 160 180 200 x= 1,000 sq. ft. GFA ♦ Actual Data Points J March 23, 2011 Figure 1 - Parking Study Results C=F) Kimley -Horn and Associates, Inc March 23, 2011 DESIGN CONSIDERATIONS The parking study conducted in February represents a snapshot of potential parking demand for a new site, and it is necessary to take into account additional correction factors, depending on the planning objectives for the site: • Seasonal Variation — Consumer spending fluctuates throughout the year, and much like a shopping center, free - standing discount superstores exhibit changing trip generation rates month -to- month. Figure 2, which represents changing trip generation rates by month for shopping centers in the United States, demonstrates that parking lot design is heavily dependent upon the design month of interest. This is typically either an "average" month, the non - December peak month, or December, the month with peak demand. Monthly Variation in Shopping Center Parking Demand 150% 140% 130% r u 12046 110% i 100% 0 w 90% c 0 70% 60% 50% F Month 5yG` Ao pe Figure 2 - Monthly Variation in Shopping Center Traffic • Effective Parking Supply — The Urban Land Institute defines effective parking supply as the number of occupied spaces at optimum operating efficiency "'. Parking lots are typically perceived as full at less than the actual total capacity, generally around 85 -95 percent occupancy. To prevent driver frustration and reduce time spent searching for open spaces, it may be necessary to take this factor into account during parking lot design. • Snow Storage — Depending on site location, snowfall may have a significant effect on usable parking supply for three to five months out of the year. It is often necessary to take this into account in the design stage, or develop contingency plans such as contracted snow removal services. C =F1 Kimley -Horn IIIIIIIIIIIIIIIIIN and Associates, Inc March 23, 2011 • Shared Parking — Some sites have the potential to utilize shared parking, particular if the peak hours of demand for each of the land uses have no overlap. Schools and churches, for example, are often compatible for shared parking reductions, and certain retail and restaurant uses may exhibit offset peak hours. All of these factors potentially play a role in the ultimate parking demand for the site, and adjustments to average observed parking demand ratios must follow from specific design objectives for the site and context sensitivity to the surrounding communities. The Chanhassen Supercenter will be located in a suburban industrial setting with no nearby street parking. As such, it may be necessary to plan for peak seasonal demand to prevent yearly parking spillover problems during the holiday shopping season. By planning for absolute peak demand, however, there will be an oversupply of parking for the remaining 11 months out of the year, making the application of additional factors such as snow storage or effective parking supply impractical. In such a case, it is reasonable to take the calculated average observed parking demand ratio, and correct for seasonal variation to obtain a design ratio for a December peak month: Parking Supply Ratio = Observed Demand / Seasonal Factor Seasonal Factor = 0.85/1.49 = 0.57 (February to December Peak) = 2.58 / 0.57 = 4.5 In the calculation, a seasonal variation factor of 0.57 is used to account for the time of year in which the parking study was conducted (February) relative to parking demand during the peak month of December. Parking generation rates at shopping centers in February represent about 85% of the demand during a typical month, and 57% of the demand during December. December demand is typically around 149% of the demand for a typical month. These seasonal adjustment factors, when taken together, allow for a final recommendation of a supply ratio of 4.5 spaces per 1,000 square feet GFA, which will provide adequate parking for the peak month during the year, December. KATWC LDEV\WALMARn704l9- 0 \DOCS \PARKING STUDY \Walmart Parking Study Memo Chanhassen Final.docx ' Parking Generation, Fourth Edition. Washington, DC: Institute of Transportation Engineers, 2010. " Smith, Mary S. Shared Parking, Second Edition. Washington, D.C.: ULI -the Urban Land Institute and the International Council of Shopping Centers, 2005. Page 14. Smith, Mary S. Shared Parking, Second Edition. Washington, D.C.: ULI -the Urban Land Institute and the International Council of Shopping Centers, 2005. Page 3.