Trooper Bryan Ball was taken to Kadlec Regional Medical Center in Richland with minor injuries Wednesday after his patrol car was hit, according to the Washington State Patrol.
Police reports say Ball had stopped on Interstate 182 near Road 68 in Pasco to investigate a collision in the median.
He was inside his patrol car parked on the inside shoulder near the collision and when it was hit at 7:12 a.m.
Cassandra Caballero, 21, of Pasco, was attempting to change lanes to get in the right-hand lane when she lost control of her car and it hit the patrol car, according to police reports.
Ball, who had neck and back injuries, was treated at Kadlec and then released, according to the state patrol.
Because his car was parked and he was working on the investigation, he was not wearing a seat belt and was not required to, according to the state patrol.
Caballero, who was wearing a seat belt, was not injured, according to the state patrol.
Her car was totaled and the patrol car had an estimated $10,000 in damage.
The collision remains under investigation, but the state patrol believes Caballero was driving too fast for conditions.
The state patrol reminds drivers that Washington has an enhanced "move over" law as of the first of this year. Drivers who fail to slow down or move over into another lane 200 feet before and after a parked emergency vehicle with its flashing lights on may face a fine of $248.
Between 2006 and 2009, passing vehicles have struck 80 Washington State Patrol trooper cars that were parked along highways.