Davies, 23, who plays for the French club Sochaux, was in serious but stable condition after a lengthy surgery at Washington Hospital Center, the hospital said in a statement.
Davies suffered a lacerated bladder and fractures to the tibia and femur bones in his right leg. He also suffered facial fractures and a left elbow fracture.
Davies was air-lifted to the hospital where a team of doctors first repaired a ruptured bladder and then inserted titanium rods in both the tibia, the bone in the lower leg, and the femur, which is the thigh bone, with no complications.
Davies will be hospitalized for at least a week and additional surgeries will be required to stabilize his left elbow fracture and possibly the facial fractures. The injuries are severe enough that Davies probably won't play in next year's World Cup.
"Injuries of this nature usually require a recovery period of six to 12 months and extensive rehabilitation," said U.S. Soccer physician Dr. Dan Kalbac, who is with the team in D.C. and collaborated with the treating doctors. "Due to Charlie's fitness level, his prognosis for recovery and his ability to resume high-level competition is substantially improved."
Davies has four goals in 17 caps, and started on Saturday when the U.S. won 3-2 at Honduras to clinch its sixth straight World Cup berth. He made his first U.S. appearance on June 2, 2007, as a substitute against China.
Born in Manchester, N.H., Davies played for Boston College before turning pro in 2006. Davies' family was en route to Washington on Tuesday, USSF spokesman Michael Kammarman said.
"Obviously, as a team we were saddened to learn this news," said U.S. head coach Bob Bradley in a statement posted on the U.S. Soccer Web site. "Our thoughts and prayers are with Charlie and his family, as well as the people in the car and the families of the others involved. As a team, we are relying on each other in a moment that has for sure hit us all hard."
One person died in the accident, which took place at about 3:15 a.m. in the southbound lanes on the George Washington Memorial Parkway in Virginia. The U.S. Park Police identified the fatality as Ashley J. Roberta, 22, of Phoenix, Md., according to Washington's NBC affiliate WRC.
U.S. Park Police Sgt. David Schlosser said there were three people in the car and that Roberta was not the driver. There were three people in the vehicle, and Roberta and Davies were passengers, according to Schlosser and USSF officials. Schlosser didn't identify the driver, who was also taken to Washington Hospital Center Medstar. The cause of the accident remained under investigation.
The U.S. team is in Washington, D.C., for its final qualifier on Wednesday night against Costa Rica.
The players were subject to a team curfew Monday night, said U.S. Soccer spokesman Neil Buethe, and Davies apparently was in violation. There was no mandatory team function until lunch on Tuesday, so officials were not aware of the accident until 11 a.m., just as Davies' surgery was about to begin. Bradley informed the players of the news as they gathered for lunch.