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HomeMy WebLinkAboutSDP200800053 Calculations 2008-05-19Kimiey -Horn and Associates, Inc. Memorandum To: Gerald Gatobu Albemarle County From: Emily Lintner, E.I.T. Carl Tewksbury, P. E. Kimley -Horn and Associates, Inc. Date: May 19, 2008 Subject: Northridge Development Parking and Traffic Analysis Update Suite 1050 222 Central Park Avenue Virginia Beach, Virginia 23462 Executive Suininarr Kimley -Horn and Associates, Inc. submitted a traffic impact analysis for the proposed Northridge development on January 25, 2008. The proposed development will be located in Albemarle County, adjacent to the existing Northridge building on Ivy Road, and will consist of a long term acute care LTAC) facility and radiology support services. Because no new parking is planned to be constructed for the new building, this report also included a parking demand analysis for the adjacent properties along Ivy Road. Since the submission of the traffic study, a preliminary site development plan has been submitted for the adjacent Sieg maintenance facility to accommodate employee parking for the existing Northridge building and proposed LTAC facility, as well as additional parking for the Moser Radiation Therapy Center. The purpose of this memorandum is to update the parking analysis previously prepared for the Northridge development and to address additional comments received from Albemarle County and the Virginia Department of Transportation VDOT). Parking analyses indicated that the peak parking demand at the existing Northridge building is 223 spaces, which leaves 33 unoccupied spaces, or 8 available spaces if a 90% occupancy is considered "full." The peak parking demand for the proposed LTAC and radiology facility was calculated to be 63 spaces, based on the total area of the building. For comparison purposes, the demand is 45 spaces if calculated based on the number of employees and only 20 spaces if calculated based on the number of beds. In order to be conservative, the highest calculation of peak parking demand (63 spaces) was utilized in the analysis. If a 10 %, surplus is to be maintained at the Northridge site, this results in a net deficiency of 55 parking spaces. Existing parking demand at the Sicg a TEL 757 213 8600 FAX 757 213 8601 Kimley -Horn and Associates. Inc. Gerald Gatobu, May 19, 2008, Page 2 of 8 site is 20 spaces, which leaves 68 unoccupied spaces. This site can accommodate the 55 parking spaces required for employees of Northridge and LTAC with a surplus of 13 parking spaces. While this surplus is one space less than the proposed requirement of 14 additional parking spaces for the Moser Radiation Therapy Center, it is anticipated that that the parking supply at both the Northridge and Sieg sites will be enough to meet the parking demand of the existing Northridge building, the proposed Northridge development, the Sieg maintenance facility, and the Moser Radiation Therapy Center because of the very conservative parking analyses that have been performed. Traffic analyses included in the January 2008 study were also conducted to represent a worst case scenario. Even with the minimal addition of traffic associated with the fire station and the Korean Community Church, the analysis and the associated recommendations in the previous study remain valid. Parkinu Analrsis Parking generation potential for the existing and proposed land uses was calculated in the January 2008 study to determine if the existing parking areas at Northridge would be adequate to support the addition of the proposed Northridge development. Parking generation rates published in Parking Generation Institute of Transportation Engineers [ITE], 3rd Edition, 2004) were utilized and supplemented with actual parking occupancy data based on field observations. Existing Northridge Building Parking Occupancy ITE Code 720 (Medical- Dental Office Building) was used to approximate the parking generation potential of the existing 58,770 square -foot (sf) Northridge building. In addition, Kimley -Horn verified existing parking inventory and collected actual occupancy data on Wednesday, December 5, 2007 at 10:00 AM, 12:00 PM, 2:00 PM, and 4:00 PM. Parking demand generated by ITE was supplemented with actual occupancy counts, and the surrounding hours were adjusted accordingly. These occupancy counts indicated a surplus of spaces throughout the day. Although the peak occupancy count was nearly identical to the peak parking demand generated by ITE, sonic have questioned the accuracy of the parking occupancy counts collected by Kimley -Horn in December 2007. Comments have been made at several meetings that parking spaces at the existing Northridge building are difficult to find and that there is no surplus. In response to this, Kimley -Horn reviewed monthly activity reports for the Northridge building to compare the number of patients seen in December, when the parking occupancy counts were collected, to the average number of patients seen per month. The reports indicated that the average number of patients seen per month in 2007 was 9,055. The number of patients seen in December 2007 was 8,359. To account for this seasonal variation, the parking occupancy data collected in December 2007 were increased by 8.3 percent. Table I below compares the hourly parking demand at the Northridge building based on ITE rates and parking occupancy counts collected in December 2007 to Kim(ey -Horn x ....0, and Associates, Inc. Gerald (iatobu, May 1 2008. Page 3 48 the increased parking demand with the seasonal factor applied. The seasonal factor results in an increased demand of 17 parking spaces during the peak demand period. Table I also indicates the number of remaining (unoccupied) parking spaces given the increased demand. Any facility that is at least 90% occupied is considered "full" by industry standards to account for circulation, turnover, and access. The number of available spaces has accordingly been reduced to account for 90"40 occupancy rather than 100% in order to maintain some surplus for circulation and turnover. A total of 254 parking spaces (88 staff and 166 visitor) are currently provided at the Northridge site. With the proposed modifications, 256 total parking spaces will be provided in the future. The unoccupied and available parking spaces determined above are based on a supply of 256 spaces. Table I— Hourly Parking Demand at Existing Northridge Building Proposed Northridge Development Parking Generation Parking demand for the proposed Northridge development was generated based on the gross floor area of the LTAC facility and radiology support services in order to provide a worst case scenario. Generating the parking demand based on gross floor area results in a significantly higher demand than if generated based on beds. Since the submission of the study, UVA Health Services has released staff projections for the LTAC facility and radiology unit. Even considering the projected number of employees, parking demand is still highest when calculated using the gross floor area. Therefore, parking demand estimates for the proposed Northridge development have not changed since the submission of the study. During the peak parking period (3:00 PM to 4:00 PM), the total parking demand for the proposed Northridge development is 85 vehicles. Based on the factored occupancy data, Table I indicates that only eight parking spaces are available during the peak demand period (10:00 AM to 12:00 PM). y a dlAssociates, Inc. Gerald G itobu, Mae 19, 2008, Page 4 of 8 Although the peak parking period occurs later than at the existing Northridge facility, the parking demand was compared to available spaces at the existing facility to determine whether additional parking spaces will be required. Table 2 summarizes the total parking demand and availability based on the increased existing parking demand with the seasonal factor applied. As indicated in Table 2, there is not sufficient parking supply at the existing Northridge building to acconunodate the parking demand from the proposed Northridge development during the period from 9:00 AM to 4:00 PM. In order to accommodate the additional parking demand and maintain a 10% surplus to account for circulation and turnover, an additional 55 parking spaces are needed to accommodate parking demand for the existing and proposed Northridge buildings. Sieg Maintenance Facility Parking In order to meet the anticipated parking demand, the UVA Health Services Foundation has indicated that they will commit to relocating some employees to the adjacent Sicg maintenance facility parking area. In order to determine the potential for future Northridge employee parking at the Sieg maintenance facility, Kimley -Horn also collected parking occupancy data at the site on Wednesday, December 5, 2007. The actual occupancy counts were compared to parking demand generated by ITE Code 150 (Warehousing) for the existing 22,610 sf building, and the actual occupancy data were found to be higher at all hours. The actual occupancy counts were therefore used for existing parking demand, with the surrounding hours adjusted accordingly. Table 3 below summarizes the parking demand at the Sieg maintenance facility by the hour and indicates the number of remaining (unoccupied) parking spaces Table 2— Hourly Parking Space Allocation at Existing Northridge u A Kimsey -Horn and Associates, Inc. Gerald Gatobu, May 19, 2008, Page 5 of K as well as the actual number of spaces available considering 90% occupancy as full." A total of 54 parking spaces are currently provided at the Sieg maintenance facility. With the proposed modifications to the site, 88 total parking spaces will be provided in the future. The unoccupied and available parking spaces determined above are based on a supply of 88 spaces. Based on the existing occupancy data, Table 3 indicates that at least 60 parking spaces are available during all hours of the day. This supply will accommodate the additional 55 parking spaces needed for the Northridge and LTAC employees while still maintaining a 10% surplus to account for turnover and circulation. Using a parking rate of 0.9 vehicles per employee (iTE Code 620), the 55 parking spaces required can be equated to approximately 61 employees. The UVA Health Services Foundation has indicated that they will commit to relocating at least 61 employees to the adjacent Sieg maintenance facility parking area. The Foundation may choose to relocate either existing Northridge employees, future LTAC employees, or a combination of the two because parking will be shared between the two facilities. It should be noted that the potential parking demand for the proposed Northridge development was generated on the conservatively high side. Actual parking conditions should be monitored periodically. The County has recently indicated that an additional 14 parking need to be constructed at the Moser Radiation Therapy Center to accommodate the building addition which is currently under construction. Because no additional parking can be constructed on the Moser site, these parking spaces will need to be accommodated at the adjacent Sieg maintenance facility. As indicated in Table 3, at least 68 parking spaces will be unoccupied during all hours of the day. If 55 parking spaces are needed for the Northridge and LTAC employees, then 13 Table 3— Hourly Parking Demand at Existing Sieg Maintenance Facility Kimfey -Horn a and Associates, Inc. Gerald Gatobu, May 19, 2008' Page 0 of 8 unoccupied parking spaces will remain for use by the Moser Radiation Therapy Center. While this surplus is one space less than the proposed parking requirement for the Moser Radiation Therapy Center, it is anticipated that that the parking supply at both the Northridge and Sicg sites will be enough to meet the parking demand of the existing Northridge building, the proposed Northridge development, the Sicg maintenance facility, and the Moser Radiation Therapy Center because of the very conservative parking analyses that have been performed. Kirtley Property Parking Generation In the previously submitted study, parking generation potential for the existing Kirtley property was also evaluated. While it is not recommended that any of the parking spaces on the existing Kirtley property be used for LTAC or Northridge employee parking, this parking has been evaluated to ensure that a sufficient supply is provided for the office and warehousing uses on the site. Table 4 below summarizes the hourly parking generation potential of these facilities. A total of 59 parking spaces (21 office and 38 warehouse) are currently provided on the Kirtley property. However, the County has indicated that 16 of the existing parking spaces which are provided on a steep grade will not be accepted. With the proposed modifications to the site and the removal of the sub - standard spaces, 32 total parking spaces (10 office and 22 warehouse) will be provided in the future. The unoccupied and available parking spaces determined above are based on a supply of 32 spaces. Table 4 indicates that at least six parking spaces will be available on the Kirtley property, even during peak times. Traffic Analysis Comments from VDOT indicate that additional proposals have recently been received by the County for additional uses on the rear parcels of the site. A fire Table 4— Hourly Parking Generation Potential of Existing Kirtley Property r' , T`4 " Kimley -Horn and Associates. Inc. Gerald Gatobu, May 19, 2008, Page 7 of 8 station is proposed to occupy 5,700 sf of the existing Kirtley warehouse building 23,100 sf) and would therefore need to access the Service Entrance for the proposed Northridge development. In addition, the Korean Community Church has proposed to construct a 6,090 sf church building, which will also utilize this access point. Traffic generation potential for the proposed Northridge development was determined using traffic generation rates published in Trip Generation (Institute of Transportation Engineers [ITE], 7th Edition, 2003). The traffic study indicated the proposed development having the potential to generate a total of 618 new daily trips, 41 of those occurring in the AM peak hour and 53 occurring in the PM peak hour. It should be noted that the trip generation potential for this site is far less than the thresholds that trigger the VDOT Chapter 527 traffic impact analysis requirements. It should also be noted that the latest site plan for the Northridge development indicates a slightly reduced total square footage compared to that which was included in the previous study. ITE does not provide trip generation rates for fire stations. However, an unlikely but worst case scenario can be assumed based on the number of employees per shift. With six employees per shift, it can be estimated that a maximum of 12 trips (6 inbound, 6 outbound) would be added per peak hour to the Service Entrance. Although a proposed service schedule for the Korean Community Church could not be provided by the County at this time, trip generation potential for the church is anticipated to be negligible during the week. Based on ITE Code 560 (Church), approximately four total trips are anticipated during each of the weekday AM and PM peak hours. Based on the previous analysis, the southbound left -turn movement fi the unsignalized Service Entrance is anticipated to operate at a level of service (LOS) D with 32.3 seconds of delay during the 2010 PM peak hour under build conditions. Based on the low trip generation potential of the fire station and church, it is anticipated that the additional trips could utilize the Service Entrance left -turns and right - tunes) without triggering LOS E conditions. It should be noted that the through volumes on Ivy Road were increased using a 5.5 ° 10 annualized growth rate through 2010 to rellect background traffic growth. This growth rate was determined from an increase in average daily traffic on Ivy Road from 12,000 vehicles per day (vpd) in 2001 to 15,000 vpd in 2005. Although it is unlikely that this growth trend will continue through 2010, the 5.5% growth rate was used to perform a conservative analysis. If the through traffic volumes grow at a slower rate, then the southbound left -turn movement at the Service Entrance will have an increased capacity and be able to accommodate more outbound traffic while maintaining an acceptable LOS. McKeeCarson and the Timmons Group have each indicated that interparcel connections cannot be provided due to significant grade differentials between the three parcels as well as the desire to maintain several existing buildings. Because some employees will be relocated to the Sieg parking area, they will be forced to Kimsey -Horn and Associates. Inc. Gerald Gatobu, May 19, 2008, Page 8 of 8 utilize the entrance to the Sieg maintenance facility if vehicular cross - access is not provided to the Northridge site. While the use of the existing entrance at the Sieg maintenance facility will increase, it is not anticipated that this will cause failing conditions at this intersection. It should also be noted that a traffic signal is warranted at the existing Northridge Main Entrance based on existing traffic volumes. Because parking at the Northridge site will continue to be fully utilized in the future, this signal will be warranted despite the relocation of some employee parking. Summary and Recommendations Parking analyses were conducted to represent a worst case scenario. In all cases, parking demand was determined using the independent variable that generated the highest peak demand or from actual occupancy counts which indicated a higher demand than calculated. In addition, the parking analyses considered conditions in which a 90% occupancy condition was considered "full." In order to provide sufficient parking for existing Northridge patients and future LTAC /radiology patients, it is recommended that 61 employees (existing Northridge or future LTAC /radiology) be relocated to the Sicg parking area. It is anticipated that all employees, patients, and visitors can be accommodated while maintaining at least a 10% surplus at both the Northridge and Sicg sites. Although the additional parking requirement for the Moser Radiation Therapy Center will consume the 100 /0 surplus at the Sicg site, a higher level of occupancy can be achieved there since it will provide parking only for employees of the facilities. Because employee parkers who are assigned to a specific parking facility will typically park in the same facility every day, they are not deterred by the need to circulate to find an available parking spot. It is also anticipated that this analysis has overstated the potential parking demand for the facilities. Actual parking conditions should be monitored periodically and adjustments should be made accordingly. Traffic analyses were also conducted to represent a worst case scenario. Trip generation potential for the proposed development was determined using the independent variable that generated the highest number of trips. In addition, through volumes on Ivy Road were increased significantly by using a high annual growth rate. The analyses therefore understate the number of gaps available on Ivy Road for traffic exiting the development, which results in overstated delay. Even with the minimal addition of traffic associated with the fire station and the Korean Community Church, the analysis and the associated recommendations in the previous study remain valid. All entrances along Ivy Road currently provide exclusive lanes for all turning movements. No additional capacity is needed for turning movements. A traffic signal is currently warranted at the Ivy Road/Northridge Main Entrance intersection and should be installed. Based on the minimal volumes at the Service Entrance and the entrance to the Sieg maintenance facility, neither of these intersections arc likely to warrant a signal in the future.