It happened just after 4:30 p.m. on westbound 360 near Skinquarter road.
An officer was taken to Chippenham Hospital. The driver of another vehicle taken to VCU Medical Center.
A Chesterfield officer had pulled over one car and was conducting a traffic stop in the 18000 block of Hull Street Road, when another vehicle crashed into the back of the police cruiser, according to police on scene.
"I heard a loud bang and I came out running and the cop was laying on his back seat saying my back is hurting, my back is hurting," said Joseph Orcutt, who lives near the accident scene.
Police said it appears the driver who hit the officer was fatigued and did not realize he was approaching the officer.