A gasoline tanker overturned on Interstate 66 near The Plains on Tuesday morning after colliding with a car that police said was making a U-turn in the highway's westbound lanes.

The drivers and the car's passenger walked away from the wreck, which destroyed both vehicles. But the tanker spilled more than 4,000 gallons of gasoline--about half its load--and I-66 westbound was closed for much of the day while crews cleaned the spill from the woods beside the road. The cleanup is expected to continue through the end of the week.

Virginia State Trooper Clifford Thomas said the accident happened about 7 a.m. when Elena McNeal, 45, of Arlington, realized she was lost. Thomas said McNeal passed an emergency-vehicle turnaround in the median about two miles west of Route 245 and stopped on the median's shoulder.

Thomas said McNeal "didn't know where she was" and decided she needed to go east instead. She backed into the restricted turnaround, Thomas said, pulled out across both westbound lanes, hesitated again and then began to make a U-turn to get back to the turnaround.

That's when the truck driver, Darrell Lewis, 35, of New Market, Va., first saw her, according to Thomas.

Thomas said Lewis assumed that McNeal was heading for the right lane, and he pulled into the left--but McNeal continued her U-turn into the path of the bright red tanker.

The impact spun McNeal's car around three times and sent it down an embankment into the woods, with the front end almost shorn off. Lewis's 1997 Freightliner truck traveled about 200 feet and turned over, sliding into trees that tore two holes in the tanker's side. All three in the accident were wearing seat belts, authorities said.

McNeal, who was treated at Fauquier Hospital for minor facial injuries and released, was charged with reckless driving, said Thomas, who added that she was "a fairly new driver." The passenger, Rosalina Receles, whose age and address is unknown, was uninjured, authorities said.

Lewis, who also was treated at Fauquier Hospital for facial cuts, works for Convenience Leasing Inc., an Altoona, Pa., trucking company. He had just picked up a full load of gasoline in Fairfax County.

"He's very fortunate," said S. Drew Jenkins, Lewis's Fairfax-based supervisor, who was at the scene of the accident. He said the losses included the truck and thousands of dollars worth of gasoline bound for a Sheetz station in western Virginia.

Westbound I-66 was closed for several hours, with traffic diverted along Route 245 to Route 17. One lane was reopened about 4 p.m., and heavy delays were reported during the afternoon rush hour. The other lane was reopened late Tuesday night after towing crews removed the wreckage.

Virginia Department of Transportation crews dumped sand in a drainage ditch where the gasoline was spreading, and fire crews threw down massive pads to help absorb it. A good portion of the poplar, oak and maple trees in the affected area may have to be destroyed and removed because of the contaminated ground, officials said.

"Nothing's going to grow there anymore," said Virginia State Police Trooper Donald Johnson, a hazardous materials expert.

"Most of the gasoline has been absorbed in the soil," said Patty Greek, a pollution response specialist with the Virginia Department of Environmental Quality. "They're going to be digging some of that soil up."

Greek said that the gasoline reached no water sources and that a Maryland-based contractor for the trucking company would handle the cleanup. The extent of the spill would be determined later in the week, she said.

VDOT officials said that the shoulder of the road may be closed as dirt and foliage are removed but that traffic is not expected to be disrupted. About 14,000 vehicles travel that stretch of the interstate daily, including about 1,400 trucks, said VDOT spokesman Jim Jennings.

In the early response to the accident, dozens of rescue vehicles, including a foam truck from Dulles International Airport, were at the scene. As Fauquier County volunteer fire and rescue crews sprayed foam around the truck to prevent the gasoline from igniting, another tanker truck pumped out the remaining fuel.