In 2010 Dana Behar, now President of Discovery Bay Investments, took an interest in solutions that would mitigate the impact of Interstate 5 in Seattle. He gathered some of the area’s leading architects, structural engineers, landscape architects, land use attorneys, transportation planners and public policy experts to brainstorm solutions. They called themselves “Lid I-5” and embarked on historical research, site analysis, and charrettes.
They worked to find ways to mitigate the damage done to Seattle when I-5 was constructed through Downtown. Some of the obvious solutions were to encourage the development of additional civic/public buildings over the freeway, such as expanding the Convention Center. Another was to create a Downtown park, which Seattle lacks, over the freeway and to expand the existing Freeway Park. One of the simplest and least expensive ways would be to simply green up the existing overpasses to make them more amenable, or to create new freeway crossings specifically for bicycles and pedestrians.
For complete lids the group determined the most affordable and feasible sections are the two blocks north of the Convention Center and the two blocks south of Freeway Park – Olive Way to Madison Street. In these areas the freeway runs in a trench below the surrounding ground level, making the covering of the freeway a relatively straightforward process. The group generated a large variety of ideas for what purposes the lids could serve; green space was a key driver, but with activating elements like an amphitheater, a space for farmers markets, outdoor play equipment, and trails.
The group also considered solutions outside of the lid area. The Yesler Way overpass, at the south end of Downtown, was found to be an opportunity because it has on-street parking and is adjacent to the Yesler Terrace public housing project; replacing the parking with landscaping and other amenities would greatly improve the walking experience to and from Downtown for thousands of residents at a relatively low cost.
The group created a website with information about freeway lids, specifically as it applies to Downtown Seattle. All of the documents, graphics, and other resources gathered by the group have been relocated to this site, with many items on the library page. Original work from the group includes a collection of concept sketches (PDF) and a presentation (PDF) on the topography of Seattle (PDF) and its interaction with Interstate 5.
The participants included the following individuals:
- Bruce Agnew, Discovery Institute Cascadia Center
- Bill Bain, NBBJ
- Lesley Bain, Weinstein AU
- Dana Behar, HAL Real Estate
- Tim Ceis, CBE Strategic
- Dan Foltz, Weber Thompson
- John Kennedy, Kennedy Architects
- Chris Libby, GGLO
- John Magnusson, Magnusson Klemenic
- Jack McCullough, McCullough Hill
- Keith Peters, Gustafson Guthrie Nichol
- Jonathan Morley, Berger Partnership
- Shannon Nichol, Gustafson Guthrie Nichol
- Denny Onslow, Harbor Properties
- Chris Raftery, Raftery CRE
- Jared Smith, Parsons Brinckerhoff
- Grant Stewart, Gustafson Guthrie Nichol
- Richard Sundberg, Architect
- David Malda, Gustafson Guthrie Nichol
- Sean Canady, GGLO
Following are a select group of images of structures over freeways. They provide a great example of what is possible.
The group’s work was made possible by the following organizations:
The following are select images from one of the group’s charrettes. Click here (PDF) for the complete document with more sketches, notes, and other information.
Lid I-5 