Officers say the suspect pulled up next to the 41-year-old man's car, firing into it through the driver's side window after an incident occurred near Blackstone Avenue at around 3:30 p.m.
The victim was struck in the left shoulder. He drove to Community Regional Medical Center and is expected to survive.
CHP officers say both the victim and suspect had female passengers in their vehicles.
Officers are investigating what led up to the shooting.
The suspect's vehicle is described as a newer model white Mercedes sedan. Anyone who has seen it is asked to contact the California Highway Patrol.