The annual Richard S. Caliguiri City of Pittsburgh Great Race returns Sunday.The 5K kicks off at 8 a.m. in Oakland. Runners in the 10K hit the pavement at 9:30 a.m. in Squirrel Hill's Frick Park. Thousands of runners will finish at Point State Park downtown.Pittsburgh Regional Transit is reminding riders that several bus routes will be detoured because of the race. Downtown, Oakland and Squirrel Hill routes are affected.More information on detours is available on the PRT website. Special buses are available to those participating in the race itself.The city has announced several closures in Downtown, Uptown, Oakland and Squirrel Hill, including Beechwood Boulevard, Forbes Avenue, Morewood Avenue and Fifth Avenue. Click here for a list of roads and approximate closure times.