Tens of thousands of people are expected to pack the streets of San Francisco on Sunday for the 42nd annual Biofreeze San Francisco Marathon.
Whether they're running, walking or merely watching, the droves of people at the event will mean road closures throughout the city, and officials are advising residents and visitors alike to plan accordingly.
Road closures have been posted at major entrances to Golden Gate Park and major roadways. There will be additional signs posted on race day at diversion points in the park, organizers said.
The race includes a marathon, half-marathon, 5K and ultra-distance run. The marathon starts at 5:30 a.m., and the other events' start times vary. But road closures will begin much earlier.
For detailed road closures, times and suggested detours, go to the official race website traffic advisory page.