In the aftermath of last January's chaotic snow emergency, officials from around the region vowed to do better next time. They convened a "snow summit," formed a task force, hashed out procedures for better communication and coordination. The end result even had a name, the Unified Regional Emergency Snow Plan.

This week, it was field-tested. The results were mixed.

"I believe things were handled well," said Fran McGrath, a maintenance engineer with the Maryland highway administration. "This was such an unusual situation. We can't always plan. We just have to adapt and do what we can from there."

But as the Washington area recovered from the unseemly preseason storm that dumped as much as 16 inches of snow on Wednesday, it also was clear that the region still has much to learn about weather conditions that are taken for granted elsewhere. Traffic jams stretched for miles, children were stuck in school buses for hours and dozens of motorists were forced to spend the night in their cars.

"We learn from every one," said Maryland state police Lt. Michael Barnes, who commands the College Park barracks.

At least some of the lessons of last winter appear to have been taken to heart. Parking restrictions were aggressively enforced, communications were much improved, and -- in an unusual show of cooperation -- authorities shared tow trucks and plows across official boundaries. "I really don't think the highway departments could have done anything any different," said Walt Starling, an airborne traffic reporter for WLTT radio who views the region's roads every day from his airplane. The snow plan, he said, is "starting to work."

But some important kinks remain to be worked out. As was the case during last year's storms, snow removal efforts were severely hobbled by hundreds of abandoned cars, particularly on the Capital Beltway between Rte. 1 in Virginia and Central Avenue in Prince George's County -- a stretch that was virtually shut down by the closing of the Woodrow Wilson Bridge.

While that crossing is a bottleneck even in good weather -- the Beltway narrows there from eight to six lanes -- officials acknowledged that a severe shortage of tow trucks aggravated the confusion.

In the same area, dozens -- perhaps hundreds -- of motorists spent the night trapped in their cars on I-295, a situation that law enforcement authorities did not become aware of until the next day.

"Obviously, we were lucky," said Prince George's County Executive Parris Glendening. "Had it been a little colder we could have had a real tragedy out there. Clearly, you can't have people sitting out 12 hours in a snowstorm, feeling absolutely isolated, potentially in danger and not having any knowledge of what's going on."

Noting that the problems on the Beltway and I-295 were related to the closing of the Wilson Bridge, Glendening said he had spoken yesterday with Maryland Gov. William Donald Schaefer about the need to keep traffic flowing over the bridge bottleneck.

"To use his term, the state got caught with its pants down," Glendening said.

The storm was widely viewed as an important test of the much-heralded regional snow plan, fashioned last summer under the auspices of the Metropolitan Washington Council of Governments. In many ways, authorities said, the region stuck closely to the prepared script.

Highway departments kept in regular contact with one another, and coordinated their efforts much more closely than in past years, participants said. Virginia, for example, dispatched troopers, tow trucks and plows to help Maryland clear the Wilson Bridge, which is Maryland's responsibility. And the District offered towing assistance to Maryland on Branch Avenue, which had become clogged with abandoned cars.

On Thursday morning, federal, state and local authorities from around the region held a 5 a.m. conference call to discuss plans for the morning rush hour, officials said.

"As far as I'm concerned, most of the elements clicked into place," said Joseph P. Yeldell, the District's emergency preparedness director. "I think the region came together, and we'll come even closer together in time."

But if the region fared well by comparison with last year, there were some important differences.

Last year, during the height of the first snowstorm, chaos prevailed when the federal government released thousands of its workers at midmorning -- hopelessly clogging area freeways before they could be plowed. This year the snowstorm occurred on a federal holiday.

"There are things, in hindsight, that we could have done better," said Maryland state police Lt. Edward Brown, the barracks commander with oversight over the worst portion of the Beltway. Brown said the storm stretched police resources well past their limits.

Nonetheless, Brown said he was mystified by reports that numerous motorists had spent the night unassisted on I-295, which extends for about an eighth of a mile into Maryland before linking up with the Beltway near the Wilson Bridge.

"We were down there," he said. "If people were stranded they would have made themselves known to us."

The District bears responsibility for policing most of I-295, but District police said they, too, had no knowledge of stranded motorists. "We had the {tow trucks} out there working pretty diligently," said D.C. police Capt. Gilbert Bussey, whose district includes the southern portion of I-295.

But officials said they would take a careful look at rescue and towing procedures before the next storm. Glendening suggested that heavy duty tow trucks could be stationed at the Wilson Bridge whenever snow is forecast. But, the District's Yeldell said, "Each storm is different."