Northgate Pedestrian and Bicycle Bridge
Updated: December 22, 2020
What’s happening now?
Long-term single-lane closure of I-5 express lane off-ramp (at 1st Ave NE and NE 103rd St)
A long-term single-lane closure of the express lane off-ramp at 1st Ave NE and NE 103rd St will remain in effect for the next several months. One lane on the express lane off-ramp will remain open during the regularly scheduled express lane daytime hours of 8 AM to 11 PM.
East side of I-5: 1st Ave NE (between NE 92nd St and NE 107th St)
- Electrical work
- Sidewall support work
- Preperation and placement of bridge spans
- Installation of temporary shoring structures
- Placement of concrete for new sidewalk and curb ramp
- Concrete work on the upper portions of the bridge for deck placement
- Placing forms and rebar cages
- Placing concrete
- Allowing concrete curing time
- Removing the forms
- Installation of cast-in-place concrete girders for what's commonly known as the "hairpin turn"
West side of I-5 (north side of North Seattle College and along N 100th St)
- Electrical work for lighting at the north entrance of the college
Upcoming work
Construction will continue through the end of 2020. In spring 2021, we'll erect 2 bridge spans over I-5. Each span will be assembled in the median of I-5, moved into place using self-propelled transporters, and lifted by cranes. We'll be in touch in the new year with information about nighttime and weekend work related to this work.Our commitment to be a good neighbor
We will keep you informed and minimize our impacts. During construction, we're committed to working closely with project neighbors and will:
- Be available for questions
- Provide advance notice about construction through email updates and other promotions
- Work closely with North Seattle College to communicate major milestones to students, faculty, and staff
- Ensure project signage is clear and effective to encourage safety and caution near active work zones
- Maintain access to businesses
What to expect during construction
- Dust, noise, and construction vehicle activity, including cranes
- Some nighttime and weekend work
- Detours for people walking and biking
- Traffic lane restrictions and closures
- Construction staging and parking impacts near the construction sites, including on the North Seattle College campus on the west side and NE 100th St (at 1st Ave NE) on the east side
- Closure of the North Seattle Park & Ride on 1st Ave NE
Long-term closure of North Seattle Park & Ride
The North Seattle Park and Ride (10001 1st Ave NE) will now be closed until fall 2021 for construction of the Northgate Ped/Bike Bridge project. The Seattle Department of Transportation is partnering with the Washington State Department of Transportation and King County Metro during the construction of the bridge. The lot will be used to stage equipment and materials for the duration of the closure. For more details, including alternative parking areas, view the full notice here.
Questions? Contact the project team at NorthgateBridge@seattle.gov
If you need this information translated, please call (206) 905-3620
Si necesita traducir esta información al español, llame al (206) 905-3620
如果您需要此信息翻譯成中文 請致電 (206) 905-3620
Project overview
The Northgate neighborhood is a major residential and employment destination that continues to grow. With the completion of Sound Transit’s Link light rail station in 2021, the neighborhood is poised to become one of the region’s most active transit hubs. Today, a 10-lane interstate divides the neighborhood, and to walk between North Seattle College and the existing transit center is 25 minutes or more.
Connecting communities on the east and west sides of I-5 in Northgate
We designed a new, accessible, all ages and abilities pedestrian and bike bridge over Interstate 5 (I-5) in Northgate. The Northgate Ped/Bike Bridge will improve access to communities, services, and opportunities on the east and west sides of I-5 in Northgate and Licton Springs, helping knit together a historically divided area. It’ll also reduce travel time for people walking and biking between the east and west sides of I-5. When complete, the bridge will help connect the neighborhood’s thriving job and retail centers with the rest of the city and region.
The new bridge will span roughly 1,900 feet over I-5, landing at North Seattle College on the west side and at 1st Ave NE and NE 100th St, near the future light rail station, on the east side.
The project consists of four main parts:
- Bridge spans over I-5
- Western approach between North Seattle College and wetland area, connecting to College Way N and N 100th St
- Eastern approach between I-5 and 1st Ave NE at NE 100th St, near the King County Transit Center
- Multi-use path along 1st Ave NE
The project will benefit the area by providing:
- A new connection over I-5, decreasing travel times for people walking and biking between the 2 sides of the highway
- Safety improvements and access for people walking and biking throughout the Northgate area
- Better access to regional transit at the King County Transit Center and future Link light rail station, resulting in increased use of transit facilities
- Improved connections between the Northgate retail center for its employees and customers and for residents and visitors to other nearby amenities, such as parks and medical and social services
Project location
Design renderings
The view from I-5 traveling north.
The user experience walking or biking across the bridge.
A view of the bridge, looking east.
1st Ave NE street improvements
1st Ave NE features
Upon project completion, 1st Ave NE will be restored and include a new 2-way protected bike lane (PBL), between 92nd and 103rd along the west side of the street (see image below).
At NE 103rd St, people biking will use the crosswalk to accessthe east side of the street, where a multi-use path or widened sidewalk will continue north to Northgate Way.
1st Ave NE will have one vehicle travel lane in each direction with a left‑turn pocket at 100th St. The existing transit center bus stops will be relocated to the east side of 1st Ave NE, between NE 100th and NE 103rd streets. King County Metro plans to restore transit stops on 1st in 2021.
North Seattle's growing bike network
Once complete, the PBL will connect with the new Northgate Bridge at NE 100th St, the existing bike lanes on 92nd, and other community connections in the area. These improvements will provide easy access to regional transit and to the citywide network of walking and biking routes.
Protected bike lanes combine the elements of a multi-use pathwith a conventional bike lane. They provide space for bikes that is separated from vehicles, parking lanes, and sidewalks.
We formed a new design team in 2016 to help reduce project costs and meet project goals. The team developed a bridge design that includes the following cost-saving changes and design improvements:
Original design (prior to 2017) | Revised design (2017 to present) |
---|---|
20-foot-wide walkway on bridge | 16-foot-wide walkway on bridge |
2,100-foot-long bridge length | Shortened bridge length to 1,900 feet |
East approach conflicted with WSDOT Park-and-Ride at 1st Ave NE | East approach modified as it touches down near 1st Ave NE, simplifying the connection and preserving the WSDOT Park-and-Ride lot |
West approach included stairs at the North Seattle College, with limited sight distance | West approach modified to improve sight distances and make a more direct connection |
Complicated construction approach | Standard construction approach to reduce project duration |
Tube/truss design (enclosed) | More open structure and more graceful bridge transition |
Finally, an added benefit of the revised design is enhanced user experience with features such as a wetland wildlife overlook and a view of arriving light rail trains at NE 100th St.
What we’ve heard through design
Based on community input throughout the project, we know there’s interest in:
- Minimizing environmental impacts of the bridge by making sure, for example, that the project doesn’t disturb wildlife during construction and ensuring the bridge’s drainage system (for stormwater) is designed to enhance wetlands on the west end
- Ensuring safety and security of all bridge travelers
- Wayfinding and traffic control
- The experience of people biking and using other wheeled devices (e.g., scooters, wheelchairs, strollers, rollerblades, suitcases, etc.)
- Connecting the bridge to other infrastructure, including neighborhood bike routes
- Separating or managing modes of traffic on the bridge
Other topics of interest included the project’s cost, the bridge’s durability, and maintaining vegetation.
We value the community input provided to date and thank you all for your continued interest.
Tree mitigation plan
Throughout our preconstruction outreach, the project team heard from many people asking about our tree mitigation plan. We will be removing 93 trees during this project, and we will be planting 464. The map below shows the full details. You can click on the map to download a PDF of the plan.
Designing for a safer bridge
During each phase (planning, design, and pre-construction) of public outreach, we heard that bridge safety is a priority for all bridge users. The sections below outline how safety is incorporated into all aspects of the bridge's design.
Design and accessibility
Throughout the design process, we used an approach called Crime Prevention Through Environmental Design (CPTED). This approach is based on the idea that people's behavior within an urban environment is influenced by the design of that environment.
CPTED strategies include things like providing ample lighting to avoid blind spots, maximizing sight distance and visibility (sometimes called "passive surveillance"), and using materials that promote easy maintenance. This strategy also aims to create spaces that give a sense of ownership of public space and a sense of shared responsibility for personal security.
There are several safety elements on the bridge, including:
- Minimal surface area for vandalism
- Overhead pedestrian lighting
- Emergency call boxes
- Pedestrian guardrails
- Lighting on handrails
- Throw fences
The City of Seattle strives to make city programs, services, and activities equally accessible to all. Our bridge design complies with 2010 ADA Standards and includes the following features:
- A bridge slope of 4.3%, except between the Sound Transit mezzanine and the NE 100th St level, which is 8.1%. This section has ADA-compliant handrail grips and 1.8%-slope landings every 30 feet to provide resting places.
- Elevator access via the Northgate Station Garage, including where the bridge connects to the Northgate Link light rail station, during normal hours of operation.
- Curb ramps along 1st Ave NE and NE 100th St, where the bridge spur lands.
- Accessible pedestrian signals at the intersection of 1st Ave NE and NE 100th St, which will offer push-button activation, audible signals, and vibrations to indicate when it's safe to cross the street.
Materials
All bridge materials and connections will go through intensive testing during construction, including the spans across I-5, which will undergo rigorous quality assurance testing during fabrication, assembly, and installation. The trusses of our bridge will be made of steel, a common and proven material and design for hundreds of bridges across the nation.
Life expectancy
Our bridge was required to meet the 75-year design life expectancy criteria consistent with the American Association of State Highway and Transportation Officials (AASHTO) design codes. Not only does our design meet this standard, it's expected to exceed a lifespan of more than 100 years with routine maintenance during its service life.
Environmental
We selected vegetation and greenery around the bridge with safety in mind. Creating park-like qualities on the trails and spaces near the bridge will provide a comfortable and enjoyable atmosphere and a "sense of place" for all users. Examples of this can be seen on the west side with a wildlife overlook, and on the east side where we're proposing a "gallery forest," or screen of tall and narrow trees between the bridge and the freeway, providing relief from views of the freeway and filtering air quality.
Additional environmental features include:
- Planting low-growing shrubs and bushes around the bridge
- Trimming, thinning, or removing existing trees and undergrowth to create open sight lines
- Carefully designed plantings on the west side of the bridge so that pedestrians on the landing will have a clearer view of North Seattle College (NSC), and those on the NSC playing field and in the parking lot will see bridge users approaching
Schedule
We expect construction to begin early 2020, and to be complete in fall 2021, prior to the opening of the Link light rail station in September 2021.
Funding
We’ve secured funding from various sources in addition to the voter-approved Move Seattle levy. These include SDOT, Sound Transit, Washington State, and additional local funds.
Stay informed
Email is the best way to stay up to date on the project during the entire construction process.
Click here to sign up to receive project email updates
Park and Ride Information
Click this link for more details about which Park and Rides are open and available throughout construction.
Outreach events
Date | Events |
---|---|
January 9, 2020 | Construction drop-in session at Olympic View Elementary |
January 8, 2020 | Construction drop-in session at Aljoya Thornton Place |
January 7, 2020 | Construction drop-in session at North Seattle College |
September 28, 2019 | Live in D5 |
September 25, 2019 | North Seattle College Fall Fest |
September 3, 2019 | Olympic View Ice Cream Social |
July 17, 2019 | Maple Leaf Summer Social |
July 13, 2019 | Live in D5 |
April 24, 2019 | North Seattle College Fair |
October 24, 2018 | Maple Leaf Community Council |
July 19, 2018 | Thornton Creek Alliance |
July 18, 2018 | Maple Leaf Summer Social |
June 30, 2018 | Live in D5! |
May 11, 2018 | North Seattle College Board of Trustees meeting |
April 18, 2018 | North Seattle College Earth Fair |
April 18, 2018 | North Seattle College Earth Fair |
March 21, 2018 | Drop-in session at Neighborcare Health at Meridian |
March 20, 2018 | Drop-in session at Aljoya Thornton Place |
March 19, 2018 | Drop-in session at North Seattle College |
February 8, 2018 | Sierra Club |
November 28, 2017 | North Seattle College campus meeting |
November 2, 2017 | Haller Lake Community Club |
August 13, 2017 | Idriss Mosque BBQ |
August 9, 2017 | Seattle Pedestrian Advisory Board Walking Tour |
August 3, 2017 | Public open house |
July 26, 2017 | Maple Leaf Summer Social |
July 22, 2017 | Live in D5! |
June 30, 2017 | Department of Neighborhoods Community Conversation Meridian Manor |
June 14, 2017 | Maple Leaf Community Council |
June 14, 2017 | Seattle Pedestrian Advisory Board |
June 7, 2017 | Seattle Bicycle Advisory Board |
May 18, 2017 | Seattle Design Commission |
May 6 | King County Metro Transit Oriented Development public meeting |
April 29, 2017 | Housing Affordability and Livability community open house (sponsored by Dept. of Neighborhoods) |
June 22, 2016 | North District Council |
May 25, 2016 | Feet First |
May 18, 2016 | Licton Springs Community Council |
May 17, 2016 | Victory Heights Community Council |
May 16, 2016 | North Seattle College (Campus meeting) |
May 5, 2016 | North Seattle College (students) |
October 15, 2015 | Public open house |
September 17, 2015 | Seattle Design Commission briefing |
August 18, 2015 | Seattle Design Commission subcommittee meeting |
July 29, 2015 | Maple Leaf Summer Social |
July 15, 2015 | North Seattle Chamber of Commerce |
June 17, 2015 | Licton Springs Community Council |
June 17, 2015 | Seattle Pedestrian Advisory Board |
June 24, 2015 | Pinehurst Community Council |
May 27, 2015 | Northwest District Council Briefing |
May 26, 2015 | Cascade Bicycle Club: Connect Northgate |
May 22, 2015 | Seattle Neighborhood Expo |
May 12, 2015 | Meadowbrook Community Council |
May 2015 | Seattle Pedestrian Advisory Board |
April 29, 2015 | Maple Leaf Community Council |
April 22, 2015 | North Seattle College Earth Day Symposium |
October 21, 2014 | North Seattle College |
September 10, 2014 | Public briefing |
June 3, 2014 | Open house |
March 2014 | Sound Transit open house |
February 2014 | Seattle Bicycle Advisory Board |
February 2014 | Seattle Pedestrian Advisory Board |
Materials
January 2020
December 2019
- Construction flyer - English
- Construction flyer - Chinese
- Construction flyer - Spanish
- Construction flyer - Russian
- Construction flyer - Vietnamese
- Construction notice
- North Seattle Park & Ride closure notice
- Final Design flyer
Environmental Review
- NEPA DCE
- Environmental Justice Discipline Report
- Hazardous Materials Tech Memo
- Fish and Wildlife Tech Memo
- Endangered Species Act - No Effects Document
- Wetland Discipline Report
- Conceptual Wetland and Watercourse Mitigation Report
- Cultural Resources Report (Section 106) and supporting documents
- 4(f)
- Crime Prevention Through Environmental Design (CPTED)
August 2018
April 2018
March 2018
- State Environmental Policy Act (SEPA) checklist
- Mitigated Determination of Non-Significance (MDNS)
- Drop-in session display boards
- Environmental review handout
- Project area mailer
February 2018 - Project information folio
December 2017 - Email update
November 2017
October 2017 - Email update
August 2017
- August Open House Summary
- Open house postcard
- Open house display boards
- Project fact sheet
- Online open house
July 2017 – Email update
June 2017
- Presentation to Bicycle Advisory Board
- Presentation to Maple Leaf Community Council
- Presentation to Pedestrian Advisory Board
April 2017 – Project fact sheet
Previous Design Materials:
October 2015
September 2015 – Seattle Design Commission presentation
June 2015 – 2015 TIGER Grant application
July 2015 – Project factsheet
November 2014 - Northgate Pedestrian and Bicycle Bridge: Alternative Development and Selection report
October 2014 – Presentation
September 2014 – Presentation
August 2014 – Presentation
June 2014
April 2014 - TIGER Grant application (Not selected. TIGER Grant is a highly competitive federal funding source)
April 2014 - Project fact sheet
February 2014 - Presentation
Background Resources
- Northgate Urban Design Framework – July 2013 (Seattle DPD)
- Northgate Pedestrian Bridge Feasibility Study Report – December 2012 (King County Department of Transportation)
- Northgate Outreach – Report on Focus Group Findings – April 2013 (Seattle DPD)
- Seattle Bicycle Advisory Board
- Seattle Bicycle Master Plan
- Seattle Department of Planning and Development - Northgate
- Seattle Neighborhood Street Fund Program
- Seattle Pedestrian Advisory Board
- Sound Transit Northgate Station Project Web Page
- Sound Transit - Transit Oriented Development Urban Design Study