More than 25,000 runners are expected to hit the streets during Saturday’s Rock’n'Roll Marathon. The race will have a major impact on drivers from Tukwila to north Seattle.

Both directions of Highway 99 will be closed at 39th Street to the north and Diagonal Ave. S. to the south starting at 5:30 a.m. All southbound lanes are expected to open at 1:15 and the northbound lanes of the viaduct at 4 p.m. with the stretch from the viaduct to 39th St. opening at 2 p.m. One northbound lane will be open for local traffic only, between Roy St and Queen Anne Drive.

The course map of the marathon can be found here (.pdf). A list of the road closures available here (.pdf).

Saturday is also the annual Greenwood Car Show from 8 a.m. to 4 p.m. Greenwood Ave. N. will be closed from N 67th St. to N 90th St.