Morgan Lake describes what it was like to fall off the Chesapeake Bay Bridge in her car, and what she did to survive. (The Washington Post)

AAA wants federal safety officials to review the barrier system Maryland uses on the Chesapeake Bay Bridge following an incident in which a woman had to swim for her life after a crash with a tractor-trailer sent her car over the wall.

State investigators were on the scene Monday, reconstructing what happened at about 8:30 p.m. Friday, when a woman in heavy beach-bound traffic was struck from behind by a truck about a quarter-mile onto the eastbound span of the bridge. The impact pushed her car over the concrete railing, and it fell 27 feet into the water, investigators said. Morgan Lake of Calvert County escaped through a shattered window and swam through 10-foot-deep water to a bridge piling, where boaters and rescue crews came to her rescue.

The AAA on Monday wrote to Deborah A.P. Hersman, chairman of the National Transportation Safety Board, asking her independent federal agency to determine whether the bridge’s railings are high enough to prevent such accidents. Much of the twin-span bridge is defined by walls known as Jersey barriers, which are less than four feet tall.

“We believe this crash merits investigation by the NTSB, and call upon your agency to undertake an investigation,” AAA said in the letter to Hersman.

An NTSB spokesman said that the letter had been received but that the agency had no immediate response.

Friday’s incident was rare but not the first. In 2008, a tractor-trailer broke through the wall after an accident on the bridge. Its driver was killed.