The H-3 freeway will be closed in both directions from 8:30 a.m. to 4 p.m. Saturday and Sunday as Hawaiian Electric crews work on upgrading transmission equipment.

Hawaiian Electric crews will be replacing a transmission tower structure with new steel poles, and relocating high-voltage transmission lines crossing the freeway this weekend.

The work is part of the utility’s ongoing efforts to upgrade the electric grid infrastructure and improve system reliability for Windward Oahu, the company said.

The temporary closure is required for the safety of the public and crews.

During the specified hours on both days, the work will close the Kaneohe-bound lanes of H-3 after the Likelike Highway offramp and the Honolulu-bound lanes after the Kamehameha Highway offramp. Also, the Kamehameha Highway on-ramp to the H-3 freeway and the offramp will be closed.

There will also be intermittent stops on Kionaole Road during the scheduled working hours.

Electronic message boards have been set up to alert motorists of the closures.

On the work days, safety signs will notify motorists of the impending freeway closure, along with electronic “arrowboards” and traffic cones to mark the work zones, according to Hawaiian Electric. Flagmen and special duty police will provide on-site traffic control.

Motorists are urged to plan ahead and seek alternate routes this weekend.