Firefighters pulled two people from an overturned vehicle on the Mission Gorge on ramp to westbound I-8.
Locals in most parts of the county awoke to steady rain causing a slow commute for many.
In one crash in the Mission Valley area, firefighters rescued a pregnant woman from an overturned SUV.
Traffic problems began before 5 a.m. when a jackknifed truck prompted a Sig Alert on northbound Interstate 805 at Plaza Boulevard in National City.
The wreckage shut down the onramp to I-805 causing a long backup for northbound traffic out of Chula Vista for about two hours.
The driver, who was not injured, told NBC 7 San Diego the crash was rain related.
There were several other fender benders along San Diego's roadways throughout the morning commute.
Then, just around 6:30 a.m., an SUV rolled over near the onramp from Mission Gorge to westbound Interstate 8.
Several drivers stopped to help but couldn't reach a woman trapped inside.
Firefighters pulled the woman from the back of the SUV while emergency crews were helping a second passenger who appeared to be injured in the rollover.
Officials said the woman rescued from the vehicle is pregnant.
The other passenger, Valerie Dailey, is in critical condition at Mercy Hospital, according to officials. There is no word on the pregnant woman's condition.