In preparation for the thousands of runners hitting Oakland’s streets this weekend, Pittsburgh Port Authority will alter more than 30 bus routes.

To accomodate the annual Richard S. Caliguiri Great Race Sunday morning, Sept. 27, Port Authority will temporarily detour 34 bus routes until approximately 1 p.m. Routes affected include the 28X Airport Flyer, the 54 North Side-Oakland-South Side routes, all four 61 routes, the 67 Monroeville route and all four 71 routes. A full list of the affected routes is available on Port Authority’s website.

The city will close streets Downtown beginning at about 5:30 a.m. and in Oakland beginning at about 6:30 a.m. The city will reopen streets at about 1 p.m.

This year, the 5K race will start at the intersection of Fifth Avenue and Atwood Street at 8 a.m. The 10K will start above Forbes Avenue on Beechwood Boulevard near Frick Park at 9:30 a.m. About 5,400 runners are registered to race in the 5K, and about 11,000 runners are registered to race in the 10K.

Port Authority will also establish two temporary bus routes — the 5K and 10K — during the time of the race to service riders between Downtown and Oakland and Downtown and Squirrel Hill, respectively. The 5K will make stops at Thackeray Avenue at Fifth Avenue and Stanwix Street at Penn Avenue on both its way toward Downtown and its way toward Oakland.

The 10K will make stops at Forbes Avenue at Beechwood Boulevard and Stanwix Street at Penn Avenue on its way toward Downtown and at Stanwix Street at Penn Avenue and Forbes Avenue at Dallas Avenue on its way toward Squirrel Hill.