Single lanes of H-1 Freeway will be closed this week to allow the state Department of Transportation to conduct guardrail and shoulder improvements.

Eastbound, there will be intermittent right lane and shoulder closures between the Lumiaina Street Overpass in Waipahu to the Kaimakani Street Overpass in 'Aiea from 8:30 a.m. to 3:45 p.m. daily through Thursday.

Also eastbound, there will be alternating left and right shoulder closures on the northbound H-2 Freeway off-ramp (Exit 8B) from 8:30 a.m. to 3:45 p.m. daily.

Also eastbound, the right lane and shoulder between the Salt Lake Boulevard onramp and Hickam AFB/Nimitz Highway off-ramp (Exit 15) from 8:30 a.m. to 3:45 p.m. daily. There will also be alternating shoulder closures on the off-ramp at this time.

Westbound, there will be intermittent right lane and shoulder closures between the Hickam Air Force Base/Kamehameha Highway on-ramp and the 'Aiea/Pearlridge off-ramp (Exit 13A) from 9:30 a.m. to 2:15 p.m., daily.

Electronic message boards will be placed at various points around the construction areas.

Motorists are advised to use caution while driving through the work areas and to allow for extra travel time. Roadwork is weather-permitting.