The actress and her husband, Jesse James of TV's "Monster Garage," were being driven in a sport-utility vehicle Friday night when a station wagon crossed the center line and hit them, said Gloucester police Lt. Jerry Cook.
Both vehicles were totaled, but no one was hurt. The vehicles were traveling 15 to 20 mph, Cook said.
The other car was driven by Lucille Gatchell, who registered a blood-alcohol level of 0.20 percent, more than twice the legal limit of 0.08 percent, Cook said.
She was held by Gloucester police overnight and released Saturday on personal recognizance. She is to be arraigned Tuesday.
Gatchell did not immediately return a call seeking comment Saturday. Calls to representatives for Bullock were not immediately returned.
Bullock, 43, was "gracious" and concerned about whether Gatchell was OK, Cook said.
The actress, who starred in such films as "Speed" and "Miss Congeniality," is in Massachusetts filming the romantic comedy "The Proposal."