As Seattle drivers deal with I-5 closure, some say it’s time to cap it

When an interstate closes for a full weekend, does it make a sound?

No. At least that’s what a small group of people gathered at downtown Seattle’s Plymouth Pillars Park Saturday afternoon were hoping when they hosted a party on a perch overlooking a half-empty Interstate 5 to celebrate a temporary reprieve from the roar of I-5 traffic.

The roar remained, however, as drivers instead flooded city streets to make their way around the region’s closed highways, part of a long-planned weekend of travel headaches.

The major work centered on this summer’s repaving of the Ship Canal Bridge, where crews are refurbishing a 900-foot-long, two-lane segment of the span, a project that closed most of the northbound interstate from its junction with Interstate 90 to Northeast 45th Street.

At the same time, work on Highway 18, the main corridor between South King County and Snoqualmie Pass, began this weekend, blocking the highway just south of its connection with I-90.

Add on the usual Seattle traffic during a summer weekend, and expect the worst.

Or not, said Tom Pearce, a spokesperson for the Washington State Department of Transportation.

“We’re just kind of seeing average travel times, maybe even in some cases, a little quicker than average,” Pearce said, surely music to the ears of North Seattle drivers.

Travelers should cheer that WSDOT didn’t also jump to work on Interstate 405. That construction will intermittently close I-405 between Aug. 22 and 25, and during weekends in September.

Still, with a significant section of the region’s busiest roadway out of commission, the roadwork was a good opportunity for people to “take a minute and consider how the interstate interacts with the city street grid, said Scott Bonjukian, who helps lead the Lid I-5 group, which is sponsored by the Seattle Parks Foundation.

Lidding the interstate – in other words, putting a bridgelike structure on top of the sunken freeway and creating land where there was none before – would hide the highway, the group argues, and make it much quieter.

While the interstate was quieter even without the lid this weekend, the roads around it growled. Pine and Pike streets and Boren Avenue were packed, as they normally are. By the pillars park, turning motorists regularly blocked the crosswalk and green bikeway.

But Bonjukian said putting a cap on the interstate – like I-90 has below Seattle’s Mount Baker neighborhood, Highway 520 has near the University of Washington and I-5 has under Freeway Park – would make Seattle a better place to live by hiding away a freeway that tore through the heart of the city.

Rob Eason, also with Lid I-5, said the idea has been proven feasible. It just needs funding and a bit of vision. The group estimated the construction costs of a lid spanning from Madison Street to Denny Way at between $1 billion and $2.5 billion, and pointed out that the recent renovation to Seattle’s Waterfront cost $800 million, and the replacement of the Alaskan Way Viaduct was $3.3 billion.

As for the vision, Eason said the lid could hold a long linear park. Or new housing.

That’s all a ways off. In the meantime, WSDOT had the foresight to use the I-5 closure to do some needed maintenance like cleaning up overgrown vegetation and replacing streetlight bulbs.

That will all end 5 a.m. Monday, when the lanes will open again in time for morning commutes. It will be a somewhat brief respite in years of planned closures related to work on the Ship Canal Bridge, which last saw major maintenance like this in the 1980s.

Sometime this fall, two southbound I-5 lanes will close during several weekends to prepare for future repaving. Next year, two northbound lanes of the entire bridge will be closed for four months. Finally, in 2027, southbound travelers will face nine months of reduced lanes.