LMN architects completes two new pedestrian and bicycle bridges in washington state

seattle-based firm LMN architects has completed new pedestrian and bicycle bridges in spokane and tukwila, cities in the US state of washington. both projects aspire to elevate the social experience for the citizens of each community, by contributing to the regeneration, well-being, and vitality of the pacific northwest. ‘one of the great things about public infrastructure projects is that they benefit the entire public,’ says howard fitzpatrick, principal at LMN.

all images by adam hunter/LMN architects

the new ‘university district gateway bridge’ is located in downtown spokane, between the city’s university district and its east sprague neighborhood. the dual-span bridge crosses over a freight railway line and east martin luther king jr. way, generating new connections within the local community and fostering new development in the traditionally under-served sprague neighborhood.

LMN says that the robust details of the 450-foot (137m) span bridge were inspired by traditional railyard bridges, while the 120-foot tall (37m) concrete arch establishes the bridge as a significant new landmark on spokane’s skyline. meanwhile, the bridge deck is suspended from the arch with thick steel cables and stout connectors, creating a visual counterpoint to the graceful curve of the bone-white arch.

the 10-foot-high (3m) throw barrier, required by the railroad, features built-in pathway lighting. at night, to ensure that the bridge is visible throughout the city, four large floodlights and the programmable color changing LED system illuminate the structure.

the bridge is anchored on the north by a spiral ramp and grand stair connecting to a new washington state university campus promenade, and on the south by a lower ramp and stair, providing access to south sherman st., sprague avenue and beyond. the ramps and stairs allow for separate parallel routes for pedestrian and cyclists at the landings, while the main span combines travel modes with clear sightlines and generous width.

the bridge and its new plazas to the north and south result in a new civic space that connects the north and south parts of the university district. intended as a symbol of urban revitalization and regeneration, the structure also hopes to spur economic growth on the south side of the tracks and linking the university with housing and retail opportunities.

‘starting with our initial mission of linking the north and south side of the university district of spokane, the project grew into much more, producing a significantly positive effect on the community and the neighborhood as a whole,’ explains walt niehoff, design partner. ‘we are proud to have worked on such an important part of the development of the city of spokane.’

titled the ‘tukwila urban center bridge’, the second crossing completed by LMN crosses the green river in tukwila, a suburban city bordering seattle at its northern edge. the watercourse flows out of the cascade mountains through communities in washington state, and is important for salmon spawning and has traditionally been a tribal fishing river in the region. the bridge has been designed to celebrate the history of the river, protect the local natural habitat, and create a new pedestrian connection between the commercial district in the west and the eastern part of the city.

inspired by tribal canoes, the 220-foot (67m) structure has a 45-foot (14m) high bowstring arch and a 16-foot (5m) wide concrete deck. on the edges of the crossing path, the bridge dematerializes and opens to the water flowing below with stainless steel grills used to reduce shade and open the surface to sunlight. this design element enhances the natural flow of the river and is important in creating a bright, welcoming habitat for salmon to swim downstream on their journey to the pacific ocean.

according to the design team, the simple form of the bridge reflects a balance between the human scale and the scale of the city, establishing a monumental presence that creates a new sense of place along the green river trail. the bridge is illuminated with LED lighting that can be modulated in different colors and light levels, creating a dynamic play of color.

the project is key to implementing the land use and transportation goals of the tukwila urban center plan and creates a safe and enjoyable walking and biking experience for the tukwila community. ‘tukwila wanted their new pedestrian bridge to be more than a convenient way to get across the green river; they wanted an icon to represent their city’s growth and vitality,’ says howard fitzpatrick.

walt niehoff adds: ‘we have had the honor to work on the new university district gateway bridge and the tukwila urban center bridge for almost ten years, and we are proud to contribute to the regeneration and vitality of each community with two projects that are open, unique and accessible to each locality. these projects reflect our design philosophy and aspire to elevate the social experience for all the residents and visitors.’

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project info:

project: university district gateway bridge
client and developer: city of spokane
design years: 2010-2014
construction years: 2017-2018
major building materials: cast-in-place concrete arch; steel deck framing; cast-in-place concrete deck; steel-framed guardrail/throw barrier with stainless steel wire mesh infill; cast-in-place concrete stairs and ramps
length: 458 ft (140 m)
height: 122 ft (37 m)
architect: LMN architects
project team:
howard fitzpatrick, AIA, mette greenshields, AIA, mark hinshaw, brianna holan, mark la venture, AIA, winnie lam, po-hsuan li, matthew mamiya, walt niehoff, AIA, ka yan tsang, associate AIA, virginia werner
landscape architect: SPVV landscape architects
lighting design: MW consulting engineers
structural engineer: KPFF consulting engineers

project: tukwila urban center bridge
client and developer: city of tukwila
design years: 2007-2017
construction years: 2016-2018
major building materials: steel tied-arch structure; steel deck framing; cast- in-place concrete and stainless steel bar grating deck; anodized aluminum guardrail
length: 220 ft (65 m)
height: 65 ft (20 m)
architect: LMN architects
project team: leonardo da costa, associate AIA, sarah durkee, howard fitzpatrick, AIA, mette greenshields, AIA, jason haase, brianna holan, amit ittyerah, keenan may, walt niehoff, AIA, erik perka, associate AIA, jeff phillips, tyler schaffer, AIA, kathy stallings, roger wallace, virginia werner
landscape architect: KPG
lighting design: KPG
structural engineer: KPFF consulting engineers