New Seattle Marathon course could slow traffic near waterfront Sunday

Seattle — Drivers should expect delays along parts of Seattle’s waterfront on Sunday as the Seattle Marathon introduces a new course that relocates the race finish line to Pier 66 and requires road closures on Alaska Way.

This change marks a major redesign of the full and half marathon routes. For years, runners finished inside Memorial Stadium at Seattle Center, but the venue is undergoing redevelopment.

“We have run the race every year at Memorial Stadium in Seattle Center, and obviously, that space is no longer available to us,” said marathon delegate John Kokas. “We found a new location that works well for us. It’s at Pier 66 downtown on the waterfront.”

Runners will still start at Fifth Avenue North and Harrison Street near Seattle Center before passing through several neighborhoods and landmarks including the Washington Park Arboretum, the University of Washington, Fremont and Myrtle Edwards Park and eventually descending toward the waterfront.

Kokas said organizers expect 8,500 to 8,600 runners this year, slightly more than last year.

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“The course passes through several neighborhoods across the city, from the Arboretum, the University of Washington, to the Fremont area and finally through Middle Edwards Park and back to the waterfront at the finish line,” he said.

Event organizers partnered with the City of Seattle, the Port of Seattle, Seattle Parks and Recreation, the University of Washington and other stakeholders to design the new routes, which aim to showcase parks, waterways and viewpoints throughout the city.

More changes are planned for 2026, when a portion of the course is expected to be relocated after construction on the Elliott Bay Trail is completed. The final two miles will diverge from Elliott Avenue onto the upgraded Waterfront Trail.

Kokas said traffic control is always one of the race’s biggest challenges, though organizers will have police officers, course marshals and representatives from the marathon’s title sponsor, the University of Washington Medical Center, stationed throughout the course.

“There are some road closures,” he said. “We are closing Alaska Highway along the coast near Pier 66, but it’s only a few blocks. Other than that, there shouldn’t be too much of an impact on traffic or anything like that.”

A list of complete road closures related to the marathon can be found here. A map of the entire route can be found here.