Honolulu police says part of Puuloa Road was closed Monday morning due to a crash investigation.
Puuloa Road between Kilihau Street and Mapunapuna Place was closed for several hours during the investigation.
The crash happened at around 6:50 a.m.
A 46-year-old woman driving a van in the makai bound direction on Puuloa Road blacked out for unknown reasons, according to investigators.
The van crossed the center line and sideswipes an on-duty police officer's vehicle. The officer, 45, was hospitalized in serious condition with and neck injuries. The woman was taken to the hospital in good condition.
The patrol officer has 12 years of experience with the Honolulu Police Department.
The road was reopened at around 10:45 a.m.
Police say it is standard procedure to close the road to investigate when an officer is involved.