Police said on Wednesday around 3:20 p.m., Officer Teresa Gilliam was stopped on the right shoulder of Interstate 85 near the Cole Mill Road exit after having pulled over a 2010 Mazda 3.
A short time later, a tractor-trailer -- driven by 44-year-old Charles Edward Caldwell of Georgia -- rear-ended Officer Gilliam's unmarked police car, pushing it into the rear of the Mazda.
Officer Gilliam was taken to the hospital, where she remains in critical condition.
The driver of the Mazda, 50-year-old Robin Gee of Greensboro, was also transported to Duke Hospital where she was treated and released.
Police said Caldwell did not receive any injuries from the crash. He has since been charged with DWI and careless and reckless driving.
According to court records obtained by ABC11, Caldwell was "weaving all over the road," going about 70 miles an hour in a 60 zone and failed to move over when he approached the stopped patrol car on the shoulder.
Officers on the scene said the" trucker had droopy eyes and slurred speech and appeared to fall asleep."
Caldwell is scheduled to appear in court in December.
In the meantime, Durham Police are expressing their appreciation for the public's support.