SAN PABLO -- A case of road rage after a vehicle collision escalated into one driver opening fire on the other, the California Highway Patrol said Monday.

A two-car crash occurred near Greenwood Drive and Greenwood Court in unincorporated Contra Costa County about 11:45 a.m., said Officer Scott Cakebread.

The drivers, who were alone in their cars, got out of their vehicles and into an argument before one of them pulled out a gun and shot the other man, Cakebread said.

The shooter ran away and has not yet been found, Cakebread said. The victim is expected to survive his injury and was taken to a hospital where he is in stable condition.

A description of the suspect was not immediately available, Cakebread said.

Contact Erin Ivie at 925-847-2122. Follow her at Twitter.com/erin_ivie.