The 40th annual Mercer Island Half Marathon Rotary Run will take place Sunday, March 25.The event kicks off with the Pre-Race Expo at the Mercer Island Community and Event Center on Saturday, March 24. The expo runs from 1 to 5 p.m.

Race day begins Sunday with ‘day of’ registration at 6:30 a.m. at the MICEC.

Various streets and areas will be closed on Sunday between 7:30 a.m. and noon, primarily around the north end. Drivers should expect delays and plan ahead. The half marathon course loops around the Island, starting at the community center, then going to East Mercer, West Mercer, North Mercer and finishing back at the community center. There will be intermittent closures as the runners make the loop around the Island.

Drivers should use Island Crest Way as the primary north/south route during these times if possible. If you must use East, West or North Mercer Way, please travel in a counterclockwise direction to minimize delays.

Closures include: West Mercer Way exit from I-90 will be closed from 7:45 a.m. until noon; avoid the 77th Avenue S.E. exit from I-90 after 8 a.m.; the Community Center parking lot will be closed all day; westbound traffic on I-90 should use the East Mercer Way exit or Island Crest Way.

The first race is the half marathon walk at 7:30 a.m., followed by the Kids Dash at 8 a.m. and the 10k run at 8:30 a.m. The half marathon run begins at 9 a.m., followed by the 5k run and walk at 9:30 a.m.

Mercer Island Half Marathon road closures:

· S.E. 24th Street between 78th Avenue S.E. and 84th Avenue S.E. will be closed both ways from 8 a.m. to noon.

· 81st Avenue S.E. closed at NMW from 7:45 a.m. to noon.

· S.E. 26th Street at the Island Crest Way ramp will be closed: 8:15-11:30 a.m.

· 2600 block of 84th Avenue S.E. to Luther Burbank will be closed: 8-10 a.m.

· North Mercer Way — from South Luther Burbank Park to Gallagher Hill will be closed intermittently: 7:30-11:30 a.m. Local traffic only.

· Shorewood Drive at 90th Avenue S.E. will be closed intermittently: 8:50-10:30 a.m.

· Gallagher Hill at S.E. 40th Street will be closed: 7:45-8:15 a.m. and 9-10 a.m.

· Southbound East Mercer Way from S.E. 36th Street to S.E. 70th Place will be closed: 9-10:30 a.m.

· Northbound West Mercer Way will be closed at S.E. 24th Street: 9 a.m.-noon. There will also be intermittent closures at this intersection as the race passes.

· Westbound S.E. 24th at 66th Avenue S.E. will be closed: 10 a.m.-noon.

· West Mercer Way off-ramp closed: 8 a.m.-noon.

There will be other intermittent closures at intersections along West Mercer Way and also near the park-and-ride as the race passes.

Learn more online at www.mercerislandhalf.com. Results will be posted online on Monday, March 26.