Part of the H-3 freeway in Windward Oahu will be closed in both directions next week as crews strengthen high-voltage transmission equipment, the Hawaiian Electric Co. said.

Work is scheduled to take place from 9 a.m. to 3 p.m. from Monday through Friday, between Kamehameha Highway and Likelike Highway. The work is expected to last four days, with Friday reserved as a contingency, HECO said.

Motorists who use the H-3 between Honolulu and Marine Corps Base Hawaii should plan their commute around the closures.

Crews are replacing a steel lattice tower — which supports high-voltage lines across the Koolau Range to power East Oahu — with stronger steel poles that are better able to withstand high winds. The existing lines, which cross over the H-3, will be transferred from the old tower to the new poles next week, requiring the closure.

Motorists should note:

>> Traffic on H-3 heading towards Marine Corps Base Hawaii will need to exit at Likelike Highway and proceed to Kamehameha Highway. Drivers can return to H-3 from Kamehameha Highway.

>> Honolulu-bound drivers on H-3 from Marine Corps Base Hawaii will have to exit onto Kamehameha Highway, then either take Likelike Highway to get back onto H-3 or take Pali Highway towards town.

>> Drivers will not be able to access the H-3 on-ramps in the Honolulu-bound direction from Kamehameha Highway.