The California Highway Patrol and the Vallejo Fire Department responded to a report of a crash on the highway east of Tennessee Street around 11:58 p.m. on Nov. 10, police said.
They located the vehicle in the bushes on the shoulder of the road between Tennessee Street and Redwood Parkway, and found that the driver had suffered gunshot wounds to his upper body.
Medical personnel pronounced the man dead at the scene.
The death marks the city's 13th homicide of the year, according to police.
Anyone with information about the case is encouraged to call Vallejo police Detective Mat Mustard or Jared Jaksch at (800) 488-9383.