I-5 Freeway Lid Plans Take Step Forward

A plan to build a cap over Interstate 5 in Downtown Seattle has taken a small but significant step forward.

1 minute read

September 30, 2019, 8:00 AM PDT

By James Brasuell @CasualBrasuell


"Data collected by engineering firm WSP indicates that it is structurally possible construct a freeway lid over Interstate 5 (I-5) in Downtown Seattle within all four of the sub-areas studied, which extend from Madison Street to Denny Way," reports Natalie Bicknell.

The feasibility study also provides key findings on the engineering capabilities of the lid in terms of development that could be added in and around the I-5 lid: "The study also found that integrating midrise and highrise buildings with the lid structure would be compatible and in some cases preferable from an engineering standpoint to deal with grade changes." For more on the development potential for the I-5 lid project, see coverage by Doug Trumm published in December 2015.

Bicknell provides detailed coverage of the feasibility study's assessment of each of the four sub areas included in the project at this early stage in planning. Sub-area one, for instance, includes the Seattle Freeway Park. Sub-area two would integrate with the Seattle Convention Center.

Friday, September 27, 2019 in The Urbanist

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