With few exceptions, north-south travel through the city will be virtually shut down during the race and police are expected to be out in force along the 12K race route.
There are some changes this year.
The word "change" makes some Bay to Breakers participants nervous; many would like to see the race stay the way it has been.
"Keep San Francisco crazy, at least for one day a year," one person said.
The spirit of the race will remain crazy, but race organizers are facing obstacles -- resident complaints and the expense of the event.
The race has lost money the past two years, but organizers are hoping a new fee will help. For the first time, all floats are required to be registered and pay a hefty $250 registration fee.
"It's definitely an expensive event to put on," race spokesperson Christy Seto said. "There's a lot of costs associated with safety as well as street closures and making sure we have great clean up afterwards."
There will be 888 portable toilets along the race course this year to help keep things tidy.
There are also new restrictions about what parts of the race the floats can participate in. In an effort to appease residents that live along the race route, floats will only participate in a mile-long section of the route.
Organizers say the new restrictions do not appear to be impacting participation; about 40 floats have been registered, in line with estimates from previous years.