A high-level D.C. public works official yesterday acknowledged that the city government erred in failing to get its salt trucks onto major arteries early enough to avoid a massive rush hour mess Friday morning.

Anne Hoey, chief of the agency's snow-fighting operations, said she accepted responsibility for the weather-related traffic problems. The congestion might have been avoided if the city's trucks, some of which were not salting major arterials until 5:30 a.m., had been on the streets 90 minutes earlier, she said.

Hoey said the District's plan of action in the early morning hours was upset when temperatures dropped below forecasted levels, sheathing roadways in heavy ice that overwhelmed the limited salting efforts then in progress.

"We thought what we were seeing at 3 a.m. was what we were going to be dealing with," she said, referring to a 3 a.m. temperature reading of 29 degrees, which was the forecasted low. "We were not expecting it to get as low as it got and refreeze, which it did . . . . As it turns out the low went down to 25. We made a decision that didn't work."

The rush hour jams drew the ire of thousands of motorists who were delayed on the way to work or, worse, victimized by numerous accidents that occurred on the city's ice-laden streets.

"We never seem to be prepared for winter weather in the District, as are places that are accustomed to snow and ice throughout the winter," said D.C. City Council member Charlene Drew Jarvis (D-Ward 4), who said she was inundated with complaints from constituents. "It really is a recurrent problem."

Officials of Accu-Weather Inc., the Pennsylvania-based firm that provides forecasting services to the Public Works Department, said they told city officials early Friday that weather conditions suggested that icing could be a problem by morning.

"I do know that the people I spoke with at 12:30 (a.m.) were advised there was quite a bit of icing in the city of Baltimore and, given that the cold air was pushing into the District from the north, there was a possibility everything would ice up in the District," said Michael A. Steinberg, director of snow warning services for the firm. Steinberg added, however, that it was uncertain at the time whether the cold air would reach Washington.

The rush hour debacle could have been avoided if the city's 30 heavy trucks assigned to salt the major arterials had been deployed earlier than 5:30, Hoey said. An additional 51 vehicles were mobilized about 6:30 a.m., the beginning of rush hour, to put salt on secondary roads, but by that time the public works vehicles were "in the traffic," bogged down like commuters caught in the slippery scenario.

"I am not sure the numbers would have made the difference," she said. "I think the error was in timing."

In addition, Hoey said, if city officials had known that the temperature would sink to 25 degrees they would have used sand, rather than salt, because sand is more effective at such temperatures.

The public works official said she monitored the situation all night from her Northwest home, relying on street inspections by city workers and reports from Accu-Weather and the National Weather Service, as well as reports from George Schoene, who heads the traffic services arm of the Public Works Department.

At 12:30 a.m., according to Accu-Weather officials, the firm issued a "storm warning," the strongest caution it provides to its clients, but it continued to forecast a low of 29 degrees.

Hoey said the forecast, coupled with reports from city workers of no actual freezing on the streets, convinced her and Schoene that road conditions would not be severe enough to warrant full mobilization. She said the agency routinely factors into its decisions the cost of dispatching workers and expending salt and sand.

Weather forecasts for today call for a 30 percent chance of snow in the afternoon, with temperatures near 35 degrees, according to the National Weather Service. The likelihood of snow will increase to 70 percent tonight as temperatures fall to 20 to 25.