At least she knows who dropped the dime.

A 51-year-old Delmar woman was charged with drunken driving Wednesday after allegedly becoming so intoxicated that she called police on herself, authorities said.

Cynthia L. Begg, of Harrison Ave., registered a blood-alcohol content of .31% — nearly four times the legal limit — when she was taken into custody around 3:50 p.m. near the busy intersection of Kenwood and Delaware avenues, police said.

The legal threshold for intoxication in New York is a BAC of .08%.

But unlike many cases in which officers are summoned by an alarmed fellow motorist or a report of a wreck, police said Begg called them herself when she realized she was way too drunk to keep going.

“She stopped driving, she pulled over and she waited for us to get there,” Bethlehem police Sgt. Stephen Kraz said. “In 16-and-a-half years, I’ve never seen that before.”

Begg, who police said was headed to another house in the Delmar area, is believed to have driven about a mile in her condition.

She was charged with DWI, driving with a blood-alcohol content over .08% and aggravated DWI for allegedly having a blood-alcohol content above .18% — all misdemeanors, Kraz said.

Begg was issued a ticket to appear in Bethlehem Town Court on April 15 at 4 p.m. and released.