The state plans to open a new H-1 freeway onramp and an offramp this week that are expected to remove traffic bottlenecks around some large shopping centers in Kapolei.

The new westbound onramp joins the freeway from Makakilo Drive. The new off-ramp leads to Farrington Highway and exits near the Wet ’n’ ild Hawaii water park.

The Department of Transportation is scheduled to open the ramps at 1 p.m. today.

The ramps are part of the first phase of the Kapolei Interchange Complex. The state expects to add new eastbound on- and offramps as well, though these aren’t due to open until August.

Federal dollars are paying for 95 percent of the first phase’s $18.7 million project cost. Kapolei Property Development LLC is paying for most of the rest.