Freeway Speed Limits to Increase Sunday : Transportation: Signs will change to 65 mph on 2,800 miles of road, including most L.A. County highways.

Starting Sunday, the maximum speed limit on about 2,800 miles of freeway in California will be increased to 65 mph from 55 mph, it was learned Monday. Another 1,400 miles are candidates for 70 mph, beginning in January.

All the major freeways in Los Angeles, Orange, Ventura and Riverside counties will increase to 65 mph, except for some of the busiest freeways through Downtown Los Angeles and parts of the South Bay, Pasadena and San Fernando Valley.

Officials of the state Department of Transportation and the California Highway Patrol, who for several weeks have been selecting which routes will be boosted to 65 mph, are scheduled to announce their choices today.

Sources said road crews will start changing the 55 mph speed limit signs to 65 mph Sunday. The new posted limits will take effect immediately. The California speed limit for trucks will remain at 55.

In the Southland, the San Diego freeway will be 65 mph, except from the Santa Monica Freeway south to to the Orange County line, including the area around Los Angeles International Airport and the South Bay curve.

The Ventura freeway will increase to 65 mph throughout Ventura County and south until it reaches Topanga Canyon Boulevard in the Valley, where it will remain at 55 mph until it joins the Hollywood Freeway. The Hollywood Freeway will remain at 55 mph.

The Santa Ana Freeway, between Downtown and the northern Orange County line, will remain at 55 mph, pending further studies. The rest of Interstate 5 will increase to 65 mph.

Under legislation signed into law last month by President Clinton, the 55 mph national speed limit--imposed by President Richard Nixon in 1974 during the energy crisis--was repealed and states became free to set their own speed restrictions.

In California, the process will occur in several phases, starting Sunday when the limit will be boosted to 65 mph on stretches of freeway where engineering and traffic safety studies have shown the higher levels are appropriate.

As a result of new legislation by state Sen. Quentin Kopp (I-San Francisco), other stretches of freeway, mostly in lightly populated rural areas, will be boosted to 70 mph starting next month, if justified by the studies. These are currently posted at 65 mph.

Officials also are examining various other routes around the state where the limit is 55 mph to determine if those limits should also be increased. The studies must be completed by March 31.

Likewise, local officials will study whether speed limits on roads in their jurisdictions can be raised to 65 mph.