An injured person in the roadway near the Kaahumanu overpass caused major traffic delays for westbound drivers.
Honolulu police are investigating the incident, which closed all westbound lanes at the Kaahumanu overpass.
The city announced around 8:10 p.m. that all lanes have been diverted to the Pearl City off ramp.
The city is asking drivers to use alternate routes when possible.
Goakamai.org reported stop and go traffic in a three mile area from Halawa to Pearl City with delays ranging from 90 minutes to two hours.