Seattle Design Commission #2 Brief
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SR 520 Montlake to Lake Washington I/C and Bridge Replacement Project SEATTLE DESIGN COMMISSION #2 BRIEF SR 520 Project Background The Washington State Department of Transportation (WSDOT) is redeveloping the Seattle segment of the State Route (SR) 520 corridor between I-5 and Lake Washington, known as the “Rest of the West”. The redevelopment will include new bridges that meet current seismic standards, updated roadways with HOV capacity and new pedestrian and bicycle facilities. In addition, the project will include a lid between Montlake Blvd E. and 24th Ave E, as well as a pedestrian and bicycle bridge over SR 520 to the east of the Montlake lid. The Montlake lid will include improved transit connections, open spaces, and enhanced non-motorized connections. Although the entire project is fully funded, funding for design and construction is allocated over several biennia. Construction is occurring in phases: • Phase 1- West Approach Bridge North • Phase 2- West Approach Bridge South and the mainline corridor spanning from Lake Washington to Montlake Blvd. This phase will include the design and construction of the Montlake lid, the Pedestrian Land Bridge, Lake Washington Boulevard and restoration of Foster Island. • Phase 3 - I-5 Express lane connection • Phase 4 - Includes replacement of the Portage Bay Bridge, a new Roanoke lid • Phase 5 – Includes a second bascule bridge over the Montlake Cut. In 2016, The Seattle Design Commission (SDC) provided recommendations to WSDOT on final design concepts related to Phase 2 of the corridor, which will be designed and constructed by a design-build contract. These SDC recommendations along with detailed input from city departments and the public assisted WSDOT in developing the 2018 Request for Proposals (RFP) for construction of Phase 2. A key change between the 2016 SDC consultation and the 2018 RFP was WSDOT allowing the use of traditional prestressed girders for the Pedestrian Land Bridge. This change to the structural approach was reviewed with the SDC prior to the RFP. Graham Construction was awarded the design/build contract for Phase 1, in partnership with T.Y. Lin, American Bridge and several subcontractors including MIG|SvR for Urban Design, Landscape Architecture and Architecture. Graham’s proposal included shortening the Lid from the west and realigning Montlake Boulevard. Page 1 of 3 SR 520 Montlake to Lake Washington I/C and Bridge Replacement Project SEATTLE DESIGN COMMISSION #2 BRIEF This change was made to allow a viable approach to protecting the 108-inch sewer line running under the current SR 520 lanes below Montlake Boulevard. Graham committed to meeting the function and character of the Lid and neighborhood open space through adherence to the “Nature Meets City” concept. The Lid revision retained the strong pedestrian buffers along Montlake Boulevard while eliminating the median to allow the space for both clearance above the sewer line and bridge clearance for traffic. The proposal reinforces the strong connection to Seattle’s Olmsted legacy through a reinforced landscape of Lake Washington Boulevard and implementing stronger regional mobility connections to the Arboretum. In 2019, the SDC began its review on the project construction contract with the Graham Team presenting the scope of the project award, the prescriptive design and technical requirements of WSDOT’s 2018 RFP plan. Project features and key urban design goals recommended by the SDC in 2016 include: • The Pedestrian Land Bridge (PLB) • The Montlake Lid (Lid) including Montlake Blvd, a Transit oriented plaza, a Neighborhood Open Space, the Portage Bay outlook and Roanoke Plaza. • The PLB and Lid connections with the local and regional trail system, the adjacent neighborhoods and the public realm • Additional view opportunities through strategically sited outlooks. • Amenities such as lighting, seating, railing etc. SDC #1 Actions Commissioners provided the following recommendations for the project team to consider as the project continues to evolve: 1. Consider reevaluating the Montlake Boulevard cross-section near Montlake Bridge to reduce the amount of pavement used 2. Achieve the gracefulness envisioned in the original concept design for the pedestrian land bridge. Consider realigning the pathway or relocating the view point if it can result in a better design 3. Continue to seek opportunities to improve upon the RFP design. Use design innovation to take advantage of design constraints, specifically as they relate to the pedestrian land bridge and plaza/open space along Montlake Boulevard Commissioners also provided insightful comments on the following issues: 1. Provide more information on the location of seating throughout the site 2. Provide consistent style for amenities such as lighting fixtures, railings, seating, etc. 3. Continue to think about how the plaza/open space will be used both for passive and active recreation 4. Continue to think about how the pedestrian land bridge will be used, specifically near the view point SR 520 Montlake Urban Design Task Force Input The Graham team schedules review sessions with WSDOT, and representatives from SDOT, Parks, OPCD and the Seattle Design Commission on key topics to receive on going feedback as the implementation design is refined. Topics covered to date include Lid open space grading, shelters, walls and treatment, outlooks, pedestrian land bridge layout, columns & nosing, Canal Reserve and SPU’s 54-inch water main vault and the various path alignments. The upcoming task force will input on the detailed implementation through the construction documents. Page 2 of 3 SR 520 Montlake to Lake Washington I/C and Bridge Replacement Project SEATTLE DESIGN COMMISSION #2 BRIEF Trees, Plantings and Maintenance: • Canal Reserve: WSDOT committed to retaining a planted buffer in the canal reserve area between the Shelby Hamlin neighborhood and the SR 520 corridor. The planting approach includes approximately 20 large conifers plus additional native and ornamental deciduous trees with a low under planting. Several of the existing trees will require removal due to the relocation of Seattle Public Utilities deep 54-inch water main and the temporary freeway off ramp. The team is working with an arborist on the treatment and protection guidance of the remaining trees. • Lake Washington Boulevard: the existing street trees on the south side of the street will remain and the planting strip east of 24th will be widened. • The tree selection and general placement is a collaboration of Seattle’s Urban Forestry, OPCD and WSDOT staff based on community feedback. (See Tree Plan) Examples include placements of: th o Yoshino Cherry’s along 24 Avenue East as a historical connection from the arboretum to the University of Washington; o Little Leaf Lindens from the Arboretum through Lake Washington Boulevard, along the approach paths to the Pedestrian Land Bridge and in the Montlake Boulevard median; o broad canopy Elms in the median in Lake Washington Boulevard and the regional shared use path; o varieties of flowering trees will be planted throughout the project area including dogwoods, magnolias, tulip trees and native cherry; o a range of medium to large conifers typical of northwest urban landscapes such as Douglas firs, Shore pines, Incense cedars etc. • The project area is extensively planted, and walls have climbing vines planted along the base. • The neighborhood open space is a green lawn with large trees and low under planting. • Maintenance: Seattle Department of Transportation, Seattle Parks and Recreation, Seattle Public Utilities, Seattle City Light and WSDOT have a maintenance agreement covering aspects from illumination, drainage, paving and signage to irrigation, plantings and amenities. July 18th SDC #2 Presentation - PLB Update and Lid (see detailed agenda) • Overview of Project and Process • Update on Pedestrian Land Bridge • Montlake Lid (Montlake Boulevard to 24th Avenue East) Fall 2019 SDC#3 Presentation – Eastern Area • including Pedestrian Land Bridge and Foster Island and follow up on outstanding topics SR 520 Montlake Project Urban Design Schedule • Urban Design Package #1 Lid CD’s – late summer through late fall 2019 • Urban Design Package #2 Eastern area including PLB & Foster Island CD’s late fall through winter 2020. • Urban Design Package #3 Mainline planting CD’s winter 2020 SR 520 Montlake Construction Schedule • Overall Construction - July 2019 -2023 • Construct Montlake Lid -2019-2022 • Construct Pedestrian Land Bridge - 2021- 2022 Page 3 of 3 2018 WSDOT RFP Plan SR 520 Montlake to Lake Washington I/C Response to RFP Plan (11/2018) SR 520 Montlake to Lake Washington I/C Refined Plan (07/2019) SR 520 Montlake to Lake Washington I/C Key Plan Pedestrian Land Bridge Concept Evolution 2018 WSDOT RFP Plan Response to RFP Plan (11/2018) Current Plan (7/2019) SR 520 Montlake to Lake Washington I/C Lid and Neighborhood Open Space SR 520 Montlake to Lake Washington I/C Transit Shelters and Canopies (2018 RFP) Transit canopy materials per RFP Technical Requirements: • Canopy decking & framing, structural decking – wood • Roof – standing seam metal, light gray finish • Columns – steel with black finish SR 520 Montlake to Lake Washington I/C Transit Shelters and Canopies SR 520 Montlake to Lake Washington I/C Tree Plan SR 520 Montlake to Lake Washington I/C Maintenance and Operations Areas Responsibilities (2018 RFP) SR 520 Montlake to Lake Washington I/C.