The driver was heading west on Sycamore Valley Road and turned south onto I-680's northbound ramp.
"That's a busy off-ramp," said Lt. Mark Williams. Traffic was coming toward her, but there were no collisions.
About 200 feet down the ramp the woman realized her mistake and made a U-turn, at which point police pulled her over and gave her a sobriety test. Her blood alcohol level was found to be more than twice the legal limit.
The San Ramon woman, Donna Parker, 43, was the nanny of two 5-year-olds who were in the car with her at the time. The children's mother came and picked them up at the scene.
Parker was arrested and charged with a DUI as well as endangering children, a felony charge.
Danville man arrested for child porn
A Danville resident and former substitute teacher for the San Ramon Valley school district was arrested Tuesday, April 8, on drug and child pornography charges.
James Joseph Meyer, 48, was charged with possessing narcotics with the intent to distribute, and possessing drug paraphernalia and child pornography.
Police believe the same man exposed himself two years ago to several 9- to 11-year-old boys.
The 2006 crime occurred in the San Ramon Creek area near Paraiso Drive, according to the Contra Costa County Sheriff's Department. The victims identified Meyer as the suspect from a photo lineup.
The investigation is still ongoing and was sent to the county District Attorney's Office on Wednesday. Contact Sgt. Dan Hoffman at 314-3703 with any pertinent information regarding this case.