The way that Joan Morris sees it, Prince William County and its surrounding jurisdictions were due for some snow.

With 90,000 tons of salt and sand stored throughout Northern Virginia, the Virginia Department of Transportation and other government agencies have been prepared to dispatch crews and plow trucks in the event of a bitter, slapping snowstorm, said Morris, a VDOT spokeswoman.

Until yesterday, however, there hadn't been much to do. After a streak of unseasonably warm days, temperatures dipped into the low twenties yesterday, and a soft, light blanket of snow fell on the county.

Unfortunately, Morris said, the department was surprised by the strength of the storm--and was late deploying crews--because meteorologists had predicted no accumulation. That contributed to traffic headaches last night across Northern Virginia, as motorists coped with the first real snow of the season. Morris said VDOT had been preparing instead for a predicted snowstorm tomorrow.

Mark Tobin, a meteorologist with AccuWeather Inc., a forecast service, said a storm system is indeed making its way toward the Washington region and is expected to bring snow showers tomorrow.

"Only the hard core mid-Westerners and those who are used to snow will say it's no big deal" when snow comes, Morris said yesterday afternoon. "But it's always been a big deal here when it snows."

To prepare, local government agencies develop contingency plans. In the days before such plans--when residents relied less heavily on government agencies to maintain the safety of the roads--people just stayed in and let the snow fall. Now, with modern technology and hundreds of workers to clear the roads, society is easier to sustain during a snowstorm, said Michael C. Moon, director of public works for Manassas.

"We've got equipment that's now used that makes it easier for the government to play a role in maintaining the standards of the community," Moon said. "On the whole, we're getting much better at doing that. We've got a goal of clearing the roads within a few hours of snowfall, and we try to do that."

Manassas reserves $120,000 to $130,000 each year for snow removal. The fund includes about 2,900 tons of salt and sand to clear the 236 lane miles the city maintains.

In nearby Manassas Park, where about $14,000 is allocated to the Public Works Department for such emergencies, crews use the city's six trucks to clear the roads, said William Weakley, director of public works.

"For the past couple of years, we really haven't had to use the salt and sand, so we've been accumulating that," Weakley said. "We're ready to go if we have to, and we'll keep the crews on call until we know for sure what's going to be happening."

In Prince William, where all the roads are maintained by VDOT, such plans include dozens of trucks with either spreaders or plows, tractors, snow blowers and hundreds of workers. When a storm strikes, crews first work to clear the interstates, major commuter routes and snow emergency routes. Once those roads are passable, crews clear residential streets, Morris said.

Modern technology that makes the clearing of roads easier includes SCAN road sensors, a statewide network of weather sensors in the roadway that allows maintenance crews to quickly identify when and where road surfaces might be freezing. Dozens of pavement sensors on Interstates 66 and 95, the Dulles Toll Road and Routes 7, 9 and 50 send real-time weather information to VDOT crews, helping them decide when and where to place the chemicals.

"It's just best to be as prepared as you can be, and all this technology helps us with that," Morris said. "Sometimes it's a blowout, but you have to be ready."

Staff writer Lyndsey Layton contributed to this report.