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HomeMy WebLinkAboutRS_Transportation Memo_Heffron_230329_v1.pdf 6544 NE 61st Street Seattle, WA 98115 206-523-3939 hefftrans.com TECHNICAL MEMORANDUM Project: Renton School District’s Hazen High School Portables Placement Subject: Transportation Analysis Date: March 1, 2023 Author: Tod S. McBryan, P.E. This memorandum summarized the transportation and parking analyses for the proposed placement of portable classrooms at Hazen High School. Please contact Tod McBryan at (206) 527-8410 with any questions regarding this memorandum. 1. Project Description 1.1. Site Description Hazen High School is located at 1101 Hoquiam Avenue NE in Renton and the site is comprised of nine parcels that total over 33 acres in size; the area of improvements is located on parcel #1023059278, which is 4.10 acres in size. The overall site is bounded by Hoquiam Avenue NE on the east, NE 10th Street on the south, Duvall Avenue NE and private residential parcels on the west, and City of Renton (City) and private residential parcels on the north. Figure 1 shows the site location and vicinity. 1.2. Project Proposal Hazen High School was last expanded in 2011; after the classroom addition it had listed capacity of 1,643 students.1 However, in response to student-teacher ratio reduction requirements (class-size reductions) in 2017, the school’s reported capacity was reduced and is currently listed at 1,462 students;2 however, the school has had higher enrollment levels for the past several years—averaging 1,650 students during the 2021-22 school year.3 To temporarily address the existing over-enrollment capacity need, the RSD proposes to place four (4) portable buildings with two classrooms each (for a total of 8 new classrooms) on the Hazen High School site. Each added portable classroom is assumed to accommodate an average of 29 students—the target capacity for RSD high schools. With the added portables, the school capacity would increase by 232 students from 1,462 to 1,694 students. This future capacity is expected to accommodate the anticipated future average enrollment at the school. No increase in the number of employees (155) is anticipated. All four of the portable buildings would be placed in the northern-most parking lot, which would displace and make unavailable 51 parking stalls. The portable placement project is planned for summer 2023 with occupancy expected by fall 2023. Figure 2 shows the site plan with the proposed locations of the portables and the parking that would be made unavailable. 1 Renton School District, Capital Facilities Plans, 2011-2016. 2 Renton School District, 2022 Capital Facilities Plan, June 2022. 3 Renton School District enrollment data. Reflects average of October and June enrollment levels for each year since number of students in high schools typically declines over course of the year. Renton School District’s Hazen High School Portables Placement – Transportation Analysis March 1, 2023 | 2 Figure 1. Site Location and Vicinity Source: Google Earth, February 2023. Annotations by Heffron Transportation, Inc. Figure 2 Site Plan with Proposed Portable Locations Source: Greene-GasawayArchitects, February 23, 2023. Project Area 1023059278 Renton School District Hazen High School Portable Placements N Renton School District’s Hazen High School Portables Placement – Transportation Analysis March 1, 2023 | 4 2. School Trip Generation As outlined in City’s Traffic Impact Analysis Policy Guidelines for New Development,4 the City requires trip generation estimates for development projects be derived using rates and equations in the most current edition of the Institute of Transportation Engineers’ [ITE] Trip Generation Manual.5 For High Schools (Land Use Code 525), the current edition provides rates and equations based on either number of students or number of employees. Because the proposed project would influence the student capacity with no expected changes to employees, rates and equations based on students were selected for this analysis. As described, the proposed project involves placement of four double portables that would increase school capacity to 1,694 students. The project would also include minor parking lot paving repairs, but no other changes. Table 1 summarizes the forecast trip generation for Hazen High School with the added capacity provided by the portable classrooms. The trip estimates for the added portables are compared to its listed capacity at the time of the last permitted classroom addition in 2011—1,643 students, since that is the level of enrollment assumed for previous SEPA review and permitting by the City. As shown, compared to its previously-permitted capacity level, the portable placement project is forecast to result in net increases of about 100 trips per day, 17 morning peak hour trips, 12 afternoon peak hour trips, and 7 PM peak hour trips. As noted, the proposed portables are planned to address an existing condition and trips being generated by the school on surrounding roadways already effectively reflect enrollment at the future capacity level. Table 1. Trip Generation Estimates – Hazen High School With Portables Capacity AM Peak Hour (6:30 to 7:30 A.M.) Afternoon Peak Hour (2:00 to 3:00 P.M.) PM Peak Hour (4:00 to 5:00 P.M.) Site Condition (Students) Daily In Out Total In Out Total In Out Total School with Portables 1 1,694 3,286 546 257 803 161 343 504 114 123 237 Existing School 2 1,643 3,187 534 252 786 157 335 492 110 120 230 Net Change 51 99 12 5 17 4 8 12 4 3 7 Source: Heffron Transportation, Inc., February 2023 using rates published for High Schools (Land Use 525) in ITE’s Trip Generation Manual, 11th Edition, Sept. 2021. 1. Capacity of Hazen High School with eight (8) portable classrooms added and reflecting class-size reductions in place since 2017. 2. Capacity of Hazen High School, 2011 Capital Facilities Plan, 2011. 3. Parking Analysis 3.1. Supply and Code Requirements Based on counts and observations conducted at the site in February 2023, the existing school site has a total of 465 striped parking stalls located in six separate areas on campus as listed below:  117 stalls in the northwestern lot between the school building and the baseball field;  101 stalls north of the school buildings;  62 stalls in the staff and visitor lot east of the main school building;  46 stalls in the lot south of Hazen Pool building;  86 stalls in the student lot south of the main school building; and  53 stalls in the south lot adjacent to the tennis courts (excludes one stall occupied by shed). 4 City of Renton, 2020. 5 ITE, 11th Edition, September 2021. Renton School District’s Hazen High School Portables Placement – Transportation Analysis March 1, 2023 | 5 The above values exclude unstriped parking that occurs adjacent to the service/delivery area. The portable-placement project would make unavailable the northerly three rows of parking (51 stalls) in the north lot. The south two rows of parking in that lot would remain with minor re-striping to create a pedestrian access path, but would maintain the same number of stalls (33 stalls) by converting them to compact. At project completion, the entire site would have a total of 414 parking stalls. The Renton Municipal Code (RMP) §4-4-080.F.10.d outlines the parking requirements for a variety of land uses, including high schools. The City requires a minimum of 1 parking stall per employee plus 1 stall for every 10 students. With the portables in place, the school is expected to have the same number of employees (155) and would have capacity for up to 1,694 students. Based on these values, the City would require a minimum of 325 parking stalls (155 + (1,694 ÷ 10)). The parking supply that would remain after the portable placement would meet the City code requirement. 3.2. Typical School-Day Demand Parking demand counts were performed at the existing school on Wednesday, February 8, 2023 at 9:00 A.M. and at 12:30 P.M. These counts found a total of 341 parked vehicles in the mid-morning and 370 parked in the early afternoon. It is noted that 61 stalls (including 35 in the lot south of the Hazen Pool building and 26 stalls in the student lot south of the main building) were unavailable during the school- day counts due to temporary construction fencing. Based on these counts and current enrollment levels, the existing school generates parking demand of about 0.20 to 0.21 vehicles per student. For comparison, demand counts were performed using aerial images of Hazen High School from May 2017 and May 2019. Those counts found a total of 394 and 336 vehicles parked on site, which correspond to rates of 0.24- and 0.20-vehicles-per-student for 2017 and 2019, respectively.6 Based on the range of parking demand rates derived specifically for Hazen High School, which already account for the target level of enrollment, the on-site parking supply of 414 stalls that would remain after portable placement would continue to accommodate the typical school-day parking demand. 4. Summary and Conclusions Compared to its previously-permitted capacity level, the portable placement project is forecast to result in net increases of about 100 trips per day, 17 morning peak hour trips, 12 afternoon peak hour trips, and 7 PM peak hour trips. However, the portable placement project is not expected to change the school’s current trip generation or parking demand levels because the school is already enrolled to the level that would be accommodated by the site with portables. The modified parking supply of 414 stalls would continue to meet the City’s minimum code requirement for parking, and accommodate the observed school-day parking demand. TSM/tsm RSD HHS Portables Placement Transportation Memo_FINAL 6 Based on enrollment of 1,618 students reported for 2017 and 1,706 students in 2019, Office of Superintendent of Public Instruction (OSPI), Report Card Enrollment Data for the beginning of each school year.