President Obama will return to Los Angeles on Friday, and the city is bracing for a repeat of extreme gridlock because of his visit.

Obama felt the sting of Angeleno road rage in August when street closures for his motorcade stretched Westside commutes from the normal 45 minutes to the duration of a one-way flight from L.A. to Chicago.

Will traffic conditions be smoother this time? Los Angeles police say don't count on it. Even in places where streets aren't closed, traffic could be affected well into the evening rush hour.

Doors are scheduled to open at 10 a.m. Friday on the USC campus for Obama's "Move America Forward" rally, scheduled for 1:30 p.m. The rally is in support of Democratic U.S. Sen. Barbara Boxer's reelection bid.

Several South L.A. thoroughfares will be closed for more than six hours in the afternoon and during rush hour. They also will be closed from 9:30 to 11:25 a.m., although some cars and pedestrians will be screened and allowed in, LAPD officials said.

Anyone traveling "in and around the USC campus" should expect delays and is encouraged to "plan another route if possible," LAPD officials said in a statement.

The closures will affect Martin Luther King Jr. Boulevard between Figueroa Street and Vermont Avenue; Vermont Avenue between Martin Luther King Jr. Boulevard and Exposition Boulevard; Figueroa Street between Martin Luther King Jr. Boulevard and 39th Street; and Exposition Boulevard between Vermont Avenue and Figueroa Street.