All lanes of the northbound 110 south of Century Boulevard were closed as authorities investigated the shooting, the California Highway Patrol announced. Lanes reopened just after 6 p.m.
CHP says the victim crashed into the right shoulder of the freeway and was helped out by a good Samaritan. Authorities later confirmed the victim was shot prior to crashing.
CHP says the shooting was reported just after 3:30 p.m. at the 105 Freeway transition to the 110.
The victim was transported and is in stable condition after being seriously wounded, according to CHP.
A traffic incident log indicated there was an act of "highway violence" at the scene. The motive for the shooting is unclear.
No suspect or vehicle description was released. The suspect was last seen going north on the 110.
Traffic was diverted onto the 105 Freeway while lanes were closed.