Jessica Kolman has gone to the Bay to Breakers race for the past 16 years because she loves the quirky, only-in-San Francisco feel of the race, which celebrates its 100th anniversary Sunday.

But Kolman, 41, of Pinole says she's worried a bevy of new rules announced by the race's organizer, including a ban on booze and floats, will take away the eclectic charm of the event and turn it into just another gentrified race, like the Boston Marathon.

"It isn't so much (the race organizers') menacing language about cracking down, but their promotional materials that don't show any costumes, just runners," she said. "Everything just seems, I don't know, too strict."

But representatives of AEG, the entertainment conglomerate that organizes the race, and the city say that last year's race, where 26 people were taken to the hospital for alcohol poisoning and neighbors had to cope with revelers vomiting or urinating in their front yards, made clear it is time for the tone of the race to change.

"Last year was the tipping point," said David Perry, who was hired by the city to help publicize the new rules. "Last year was such a mess that organizers, the city and (police) decided we had to change something."

"It is like that old Barbra Streisand-Donna Summer duet: 'Enough Is Enough,' " he added.

The negative attention made it hard to attract race sponsors. This year, Internet company Zazzle didn't sign on until mid-March, long after ING declined to renew its lead sponsorship agreement.

Checkpoints on route

This year the race will have a handful of checkpoints - police won't say how many - scattered along the route. There, police officers and private security guards will screen racers and revelers to make sure they are properly registered and aren't intoxicated.

Only 55,000 runners were allowed to register. Those who haven't paid the $75 registration fee will be asked to leave the route and not be allowed to return.

Open containers of alcohol will be confiscated. Any intoxicated person - runner or spectator - will be sent to a "drunk tent" where they will be held until sober, said police Cmdr. James Dudley, who is coordinating the police response to the event.

If intoxicated runners decline to wait in the tent, they will be cited and taken to jail or a community drug center, he said. "The focus is to remove those folks from the race."

Police will also keep an eye on the 100,000 spectators expected to watch the race, organizers said.

Forget the floats

All floats, which are sometimes quite creative but other times as simple as a keg in a shopping cart, willbe confiscated at any of the checkpoints. The race will start at 7 a.m., one hour earlier than it did last year.

The goal of the new rules is not to kill the party, said Sam Singer, spokesman for the race organizer, but to control what Supervisor Ross Mirkarimi calls the "knucklehead element," he said.

"You can come in costume, come naked, just don't come drunk," Singer said.

Fans of the race complain the new rules will kill the free spirit of the race and are part of a larger "war on fun" in San Francisco.

"It is a fear tactic," said Ed Sharpless of Citizens for the Preservation of Bay2Breakers. "These guys have been trying to sanitize the race for three years. They are trying everything they can."

More than 15,000 people subscribe to the group's Facebook page, where many have discussed the best ways to hide alcohol or sneak through the checkpoints without the required registration number.

Some have planned protest "salmon runs" that will start at the opposite end of the race course and run toward the rest.

The real problem is the small percentage of revelers who will always drink too much, Sharpless said. It isn't fair to penalize every person who is looking to have fun.

Wanting more toilets

If the race organizer provided enough toilets, he said, there would be fewer reports of people urinating or vomiting in public.

"The overwhelming majority of people who are drinking are responsible professionals who just want to blow off steam, not drunken knuckleheads," he said.

While the new rules might not dampen the spirits of some runners, the expected rain and cold certainly will, said Mike Pechner, a private meteorologist.

"An unseasonably cold weather system from the Gulf of Alaska will sweep into the Bay Area this weekend with showers or thunderstorms and record cold temperatures," he said in an e-mail.

BART and Caltrain will be running special schedules to get people to and from the race.

A number of people expected to attend the party said they understood why the rules were put into place but had no intention of following them.

Hayley Hammershaim, a 23-year-old senior at UC Berkeley, said she's hoping to celebrate her graduation at the race. She and her friends are not registered, and she admits they plan to sneak a drink or two during the race.

"I am a little worried," she said. "But I feel like so many people are drinking, I don't see how they are going to stop everyone."