Alpharetta is warning motorists to expect heavy delays and to try to avoid the downtown area at the tail end of the afternoon rush hour Thursday, Aug. 23, because of the Mayor’s Corporate Challenge 5K road race.

The following street closures are planned:

Park Plaza, 3 to 11 p.m.: All lanes closed between Academy Street and Haynes Bridge Road. The parking deck next to City Hall and the library will be accessible from Main Street.

Haynes Bridge Road, 6:20 to 8 p.m.: all lanes closed between Old Milton Parkway and Academy.

Academy Street, 6:45 to 7:40 p.m.: all lanes closed between Main Street (Ga. 9) and Westside Parkway.

Westside Parkway, 6:45 to 7:50 p.m.: One of two southwest-bound lanes closed between Academy/Webb Bridge Road and Old Milton.

Old Milton Parkway, 6:50 to 8 p.m.: one of the three westbound lanes closed between Westside and Haynes Bridge.

Festivities begin at 5 p.m., with a free kid's fun run at 6:30 p.m. and the 5K starting at 7 p.m. Information: https://www.mayorschallenge.com/

The Mayor’s Corporate Challenge attracts thousands of people annually for an evening of food, music and running. It raises more than $100,000 for local nonprofit organizations, supported by the Rotary Club of Alpharetta, that serve the homeless.