With Quercetti on the hood, the vehicle swerved into the center lane and then the grassy median for 60 to 70 feet and back onto the road before the victim fell off.
"We are lucky he didn't get hit again," said Joseph Daly, Springfield Township police chief.
"When [the driver] hit this kid, they never slowed down. There is no indication on the road of any attempt to stop."
Some evidence left at the scene, Daly said, has been sent to a state lab. Another motorist, a 22-year-old man from Upper Darby, saw what he believed to be a person lying on the road. He turned around, stopped, and called police at 2:45 a.m., Daly said.
Quercetti was not carrying identification. Police were able to get his identity by tracing a receipt in his pocket and comparing the name, previous hospital records, and photos from a state database, Daly said.
Quercetti's car was close to the accident scene, near his friend's house, Daly said. Police do not know why he was walking along the road.
Quercetti was in critical condition at Crozer-Chester Medical Center with head trauma and a broken leg and shoulder, said Al Quercetti, 59, his uncle.
The family has offered a reward for information about the driver. It has not disclosed the amount.
Thomas Quercetti is a Cardinal O'Hara High School graduate who works at the family's Dairy Queen store in Aston, his uncle said. He described his nephew as a "motor head" who loves four-wheelers and dirt bikes. "He is an upbeat, happy-type guy," Al Quercetti said. Family members have gathered at the hospital to support one another and pray.
Not knowing how the accident happened or who caused it has been hard, Al Quercetti said. "We would just hope that they would care enough and have a conscience to do what is right and just come forward."
The vehicle that struck Thomas Quercetti should have damage to the front bumper, headlights, hood, and windshield, police said.
Anyone with information is asked to call Springfield Township detectives at 610-544-5504.
Contact Mari A. Schaefer at 610-892-9149, email@example.com or @MariSchaefer on Twitter.