A bullet pierced a pick-up truck's rear window on Highway 4 near Bailey Road in Pittsburg Friday night.
At least two people were in the westbound vehicle during the shooting around 9 p.m., but neither suffered gunshot wounds. A female passenger, who was hurt by flying glass shards, was taken to an area hospital with non-life threatening injuries, Contra Costa County sheriff's officials said.
The driver, who said he heard a pop and then saw the shattered rear window, decided to pull off Highway 4 at the Willow Pass Road exit. He parked in a Chevron gas station, which was soon swarming with sheriff's officials.
"The important part is that everyone was okay, luckily," Lt. Ian Hebert said.
Sheriff's officials said someone opened fire from a nearby vehicle, but they did not provide details about the possible shooter or suspect vehicle. Officials have also not commented on whether the shooting was gang-related.
More than 20 shootings have plagued East Bay highways since last November.
Further details were not immediately available.
Bay City News contributed to this report.