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the 'motion' design is inspired by the flow of the ottawa river and the sacred eel.
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national capital commission
motion, a graceful triple-arched bridge inspired by the flow of the ottawa river and the endangered american eel, has been chosen as the design to replace the aging 124-year-old alexandra bridge.
the national capital commission unveiled the design at its jan. 23 board meeting, following months of study and public consultation. motion is one of three designs shortlisted for the new bridge, the construction of which is set to begin in 2028.
the others were echo, a modernized take that preserved the distinctive outline of the existing bridge, and rendez vous, which had two spans of 290 metres and 220 metres suported by a single pier in the river closer to the quebec side. rendez vous has two arches, compared to the triple arch of motion, and would be 15 metres taller than the existing towers on the alexandra bridge.
the ncc used seven objectives to evaluate the designs:
- bridge expression
- integration into the capital and natural landscape
- public space and user experience
- views and visual experience
- sustainability and the environment
- construction cost and schedule
- operation and maintenance
all three designs scored well and exceeded the minimum threshold, but motion placed first when scores were averaged, said bruno fabien, director of engineering assets for the ncc. motion scored particularly well in the amount of public space it would provide and for its visual experience, he said.
the design gives “a balance between transparency and mass to highlight symbols of the natural landscape” while providing “captivating and enhanced” views from both upstream and downstream, he said.
motion also has the lowest slopes on its approaches.
“in terms of user experience, motion stands out from the other concepts,” fabien said.
motion incorporates a pedestrian walkway with viewing areas on the west, upstream side of the bridge, while two lanes of traffic and a separate space for bicycles would be contained within the width of the archways.
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echo most closely matched the look of the alexandra bridge’s distinctive profile, but “the opacity of the structure and irregularity of the design across the span introduced some complexities that could influence the experience of users.” he said.
rendez vous had the least environmental impact because of its single pier, but was significantly taller and had more impact on the city skyline. it also scored lower than motion on how well it reflected the natural landscape, he said.
the national capital commission released three renderings of a replacement for the soon-to-be-demolished alexandra bridge. this is a rendering of the proposed design “motion.”
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national capital commission
the ncc held two open houses in october that attracted some 350 people. it also received 1,900 comments on social media and nearly 5,200 online submissions.
it did not, however, ask the public to choose among the three designs.
“we did not ask the public to rank each concept. what we asked them was what they appreciated about each concept and what they would like to improve,” the ncc’s manager of public consultation, emilie girard ruel, said when asked by reporters.
“we saw all three concepts were appreciated by the public and all three were very positively received.”
(an online, and admittedly unscientific, poll by the ottawa citizen last fall showed nearly 60 per cent of respondents said they liked echo the best, while motion was the least popular with just 19 per cent support.)
all three designs would cost about the same to build, but the government isn’t saying how much it will cost to demolish the existing bridge and build the new one.
“the costing will continue to evolve throughout the design phase,” stefan dery, director general, infrastructure asset management with public services and procurement canada, told reporters. “it’s a little premature for us to disclose that information at this time, also noting the fact that we’re in the act of a competitive procurement process.”
the replacement is a joint project of the ncc and public services and procurement canada. built in 1901 as a truss-style railway bridge, the alexandra bridge carried about nine per cent of the vehicle traffic between ottawa and gatineau and 33 per cent of bicycle and active-use travel. despite numerous upgrades, years of road salt use have corroded the structure to a point it can no longer be repaired.
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a complete design of the new bridge is expected to come back to the ncc board for approval in late 2025.
this is a rendering of the proposed design “motion.”
national capital commission
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