It's more deadly to drive on Maryland's stretch of the Capital Beltway than Virginia's, the leading trucking industry group said yesterday.

All 15 traffic deaths on the Beltway in a one-year period ending June 30, 1990, occurred in Maryland, according to figures compiled by both states and presented yesterday by the American Trucking Associations. There was a total of about 3,000 accidents in both states in that period.

The trucking industry group called a news conference to offer information and advice on how to drive on the 66-mile Beltway, the main highway circling the region. The truckers are trying to counter frequent criticism from drivers by showing that trucks are involved in proportionately fewer accidents than automobiles.

Although more people travel on Virginia's 23 miles, Maryland's 43 miles of the Beltway are more dangerous, the group found.

Thomas J. Donohue, president and chief executive officer of the associations,, said the higher death toll in Maryland probably was related to the narrow configuration of the highway in places such as between the Wisconsin Avenue, Connecticut Avenue and Georgia Avenue exits.

He said the Beltway presents a political problem for the trucking industry because whenever members of Congress are tied up from a Beltway accident involving a truck, "it's hard to talk to them about trucking issues."

The most common time to be involved in a Beltway accident is between 5 and 6 p.m. on Friday, the associations said. Six of every 10 accidents are caused by drivers not paying attention, the group said.

The five most dangerous segments of the Beltway in Maryland are the exits at Route 1; the Baltimore-Washington Parkway; Route 50; River Road; and University Boulevard.

The most dangerous Virginia segments are between Route 193 and the George Washington Parkway; between the Shirley Highway and Telegraph Road; between Telegraph Road and the Maryland line; and between Braddock Road and the Interstate 95/Shirley Highway interchange.