At about 5:30 p.m. Sunday, Pikesville firefighters responded to a call of a vehicle accident at I-695 near the Liberty Road exit, said Sgt. Kirchner of the Golden Ring State Police Barracks.

"For an unknown reason, the driver left the roadway and struck the guardrail and became trapped between two trees," Kirchner said. Only one vehicle was involved, and one person was in the vehicle.

The accident occurred on the outer loop of I-695, Kirchner said.

The driver, whose name is not yet available, was taken to University of Maryland Shock Trauma Center, Kirchner said.

State Police and firefighters from Baltimore County Fire Department's Station No. 2 rescued the driver, he said.

Pikesville Volunteer Fire Company's Medic 325 was the first to arrive at the scene, company spokesman Michael Schwartzberg said in an e-mail.

The accident, in which the vehicle was suspended 10 feet above the ground and over a creek bed, caused traffic backups through about 7 p.m., Schwartzberg said.