The rockfall closed the road in both directions at 4:11 a.m., but state road crews were able to open the road to contra-flow traffic about an hour later. Both lanes were reopened at 9 a.m.

State Transportation Department spokesman Scott Ishikawa said one of two car-engine size boulders that fell from the top of the hillside made it onto the roadway.

Fencing set up by the state prevented one boulder from reaching the road, but the other went through an unprotected area, Ishikawa said.

DOT plans to set up concrete barriers to cover the previously unprotected area, according to Ishikawa.