Honolulu police said all lanes on the Moanalua Freeway reopened Thursday night after several boulders closed three lanes.
It happened on the eastbound lanes near the Tripler Medical Center off-ramp just before 7 p.m. causing a vehicle crash. Police say no one had major injuries.
Police said traffic crews worked to secure the area and remove the hazardous rocks.
Three mauka lanes were closed for nearly two hours.
The Department of Transportation said the boulders were cleared by 11 p.m. One large boulder broke into several pieces. One piece was 3.5 feet in diameter.
An engineer was scheduled to go back to the scene on Friday. The state is looking into whose property the boulder came from.