COLUMBUS, Ohio (WSYX) — The Nationwide Children’s Hospital Columbus Marathon, the biggest race weekend of the year, kicks off in the city on Saturday.

The event is expected to attract 100,000 spectators cheering on the athletes throughout the weekend.

Nationwide will host a series of races including a half marathon, a 5K and a 1 mile run on Saturday at 11am, followed by a children’s run at 1pm. The marathon and half marathon take place on Sunday, with races starting at 7:30 am

The influx of crowds means drivers should prepare for road closures and detours in the downtown area. At least seventeen COTA buses will be diverted on Sunday morning and early afternoon. Nearly all downtown transit stops will be closed beginning at 4 a.m. Sunday, impacting more than 800 transit stops in the surrounding areas, including Short North, Upper Arlington, OSU and Grandview.

The marathon will feature 3,000 volunteers, 15,000 athletes from across the country and 100 bands and entertainers.

The race course includes nearly 4 miles of fencing, a 201,600-watt sound system at the starting line and 27 permits across five police jurisdictions to close 26 miles of roadways.

To keep participants hydrated, 200,000 White Castle cups of water, another 200,000 cups of lemon-lime Gatorade, 16,000 bananas and 600 portable bathrooms will be available for use.