Four members of a Chevy Chase family were injured yesterday - three seriously - when a tractor trailer crashed into the back of their car on Route 50 East in Anne Arundel County, Maryland state police reported.

Mary Anne Berberich, 38, of 3909 Montrose Driveway, was listed in stable condition in Anne Arundel County General Hospital after suffering multiple injuries.

Two children, Kathryn Berberich, and Kathryn Farrell, a family friend, both 10, were taken to the children's ward at Johns Hopkins University Hospital where they are being treated for multiple injuries. Mathew Berberich, 7, is in stable condition at Anne Arundel County General Hospital.

Dr. Leo Robert Berberich, 41, the driver of the car, was treated for minor injuries at Anne Arundel Hospital and released.

Police said the Berberich car, which was towing a boat, was traveling castbound on Route 50 in a passing lane shortly after 6 a.m. when the accident occurred. The berberich car made a sudden switch into the right-hand lane. Police said, and a tractor trailer, which was in the right lane, was unable to stop in time to avoid a collision.

The trailer pushed the car about 100 feet before the trailer overturned, blocking three lanes of traffic, police said. Charles Morris, of Richmond, the driver of the truck, was treated for minor injuries at Anne Arundel Hospital and released, officials said.

The truck is owned by the William David Trawick Trucking Co., Garner, N.C., police said.