In some cities, championship games have brought costly and, occasionally, deadly riots.

Pittsburgh Mayor Bob O'Connor said he doesn't anticipate postgame problems Sunday night but is preparing a multi-agency police presence and closing many streets just in case. Details were released yesterday.

"Let's hope it's a fun celebration," he said. "You always have to be prepared."

The Police Bureau declined to release an exact number of city officers that will be on duty.

Fraternal Order of Police President Michael Havens said the afternoon-evening shift and the night shift would be combined, and some detectives were being called in. "I'm assuming it's going to be 500 to 550" city officers on duty, he said.

The bureau has 820 officers.

Sixty state troopers and their Special Emergency Response Team will be on the streets or on standby, the city police said, as will a state mounted patrol and a helicopter unit.

The Allegheny County Sheriff's Office will have three squads of 15 deputies each in South Side, Oakland and the North Side. Another squad will be on standby, said Sheriff Pete DeFazio. "They'll be transporting all the arrests," he said of the four squads.

The county police will add six mounted units, said Superintendent Charles Moffatt.

Thirty-five University of Pittsburgh police will patrol Oakland, and will close off Bigelow Boulevard between Fifth Avenue and Forbes Avenue, said Pitt Police Chief Tim Delaney. "We're targeting Bigelow [as a spot for celebration] because we know we can hold 5,000 people comfortably," he said.

Sixteen Port Authority police, plus the transit agency's three K-9 units, will round out the team.

The Wood Street Station Downtown will close at 10 p.m. to allow police to fan out through the transit system.

The Allegheny County Jail will add 12 correctional officers to its Sunday night shift, which normally has about 80 officers, Warden Ramon Rustin said.

"I'm hoping they won't be needed," he said.

The jail also has ordered extra eye wash to treat people who have been exposed to tear gas. At the Municipal Courts building, next to the jail, there will be more district judges and bail bondsmen on hand.

"We're just going to have high visibility, like after the AFC Championship," Mr. O'Connor said.

"You don't want to mix traffic and people," he said. So starting at 9 p.m., parts of many streets will be closed to all but emergency vehicles, commercial trucks and buses, and residents with proof of address.

The partially closed streets and spans include Carson Street, the Hot Metal Bridge and the Birmingham Bridge on South Side; Forbes Avenue, Bates Street and possibly both Parkway East exits in Oakland; Penn Avenue and Smallman Street in the Strip District; the Clemente Bridge to the North Side; and parts of major Downtown arteries.

Police will check for drunken drivers at spots "throughout the city," the bureau said.

Port Authority buses will be on standard Sunday schedules, but will be detoured. All inbound trips will end, and outbound trips begin, at one of three locations: Penn Station along the Martin Luther King, Jr. East Busway; Grant Street near Steel Plaza Station; and First Avenue next to First Avenue Station.

When the Steelers last made the big game in 1996, some 340 police dispersed from Downtown alone to prevent riots. The Steelers lost to the Dallas Cowboys, and the bureau reported only two arrests, both for drunken driving.

Other towns haven't been so fortunate.

In 2003, the Oakland Raiders' defeat by the Tampa Bay Buccaneers prompted fans of the losers to burn 10 cars and a restaurant, and pelt firefighters with bottles and rocks.

In 2004, students at Boston's Northeastern University rioted after the New England Patriots beat the Carolina Panthers. One young man died.

"Let's show off our team and our pride, and our ability to have a good time responsibly," Mr. O'Connor said.