A sudden, unpredicted temperature drop just before dawn yesterday put a thin film of ice on bridges and overpasses in the Washington area, causing numerous traffic accidents and leaving three dead and dozens injured.

In the most serious accident, three tractor-trailers and a car collided on the icy I-66 bridge over Rte. 29 in Prince William County, killing three persons, including a retired Arlington couple on their way to a funeral.

"Rush hour was a mess," said Tom Crosby, spokesman for the Washington-area American Automobile Association.

Northern Virginia was most seriously affected, authorities said, with 74 accidents reported in Fairfax County, 11 in Arlington and 17 in Alexandria, almost all on bridges or overpasses. District police said they had no major problems; roads and bridges were clear. In Maryland, the icy conditions resulted in fender-benders but no serious accidents.

Joe Cope, a forecaster with the National Weather Service, said the weather today should be clear, with temperatures in the mid-30s, and he predicted the weekend would provide another taste of Indian summer, with clear skies and temperatures in the mid-50s through Monday.

The weather service said it had not anticipated yesterday's predawn dip in temperatures that iced roadways wet from Wednesday evening's rain.

The icy bridges took police and road maintenance officials, as well as commuters, by surprise. "It just came up all at once," said Virginia State Police Sgt. W.E. Moore. "Nobody was actually prepared for it."

Lynda South, a spokeswoman for the Virginia Department of Highways and Transportation, said that between 5 and 5:30 a.m., crews reported all bridges clear, but that at 5:45 a.m. the temperature dropped suddenly and iced over every bridge. By 7 a.m., the department had 45 sand trucks on the road, but it was the sun that melted the ice just as rush hour was ending.

William C. Furrow Jr., 67, and his wife Lenna, 65, of Arlington, and David Forrest, 37, of Chicago, died in yesterday's only fatal accident, according to Virginia State Trooper C.E. Blosser.

Just after 5 a.m., Blosser said, a westbound moving van skidded out of control on the long, icy bridge where I-66 crosses Rte. 29. The van overturned with two persons trapped inside.

Several minutes later, Blosser said, a tractor-trailer carrying frozen food slammed into the moving van, slicing off its back end and strewing the road with household belongings. The food truck jackknifed with two persons trapped in its cab.

A third truck, driven by Noton Chambers, 58, of Baltimore, came across the bridge, clipping the moving van but coming to a halt upright.

Chambers, who was only slightly injured, was setting up warning flares when a red 1981 Volkswagen driven by William Furrow came across the bridge in the left lane. Furrow apparently did not see the overturned moving van in the darkness and fog, and slammed into it at 50 mph.

Furrow, of 1160 S. Thomas St., Arlington, was killed instantly, Blosser said. His wife died later in surgery at Fairfax Hospital. Blosser said the couple was on the way to the funeral of Mr. Furrow's sister.

Forrest was a passenger in the moving van. His father, Nehemiah Forrest, 63, also of Chicago, was driving the truck and was in stable condition in Prince William Hospital.

Norma Bartley, 38, of Belle Fontine, Ohio, a passenger in the frozen-food truck, was in critical condition in Fairfax Hospital. Her husband, Jackie Bartley, who was driving the truck, was treated and released.