Starting tomorrow, three people will required for a car to use the H-1 Zipper Lane and Nimitz Highway contraflow lanes.

All other high-occupancy vehicle lanes on Kalaniana'ole Highway, H-2 and Moanalua Freeway will require two occupants per vehicle, said Brennon Morioka, state Department of Transportation director.

The change was because it was actually taking longer by as much as 20 minutes to be in the Zipper Lane than in the regular lanes, said Morioka at a news conference from the Radford Drive overpass.

"The lanes are not working as efficiently as we had hoped," Morioka said. "The whole purpose is to move people in less time. Those people who had been carpooling are now in other lanes and that means more cars on the road."

The Zipper Lane went into effect in 1998. At the time, three occupants were required to use the lane in the morning commute from Waikele to Nimitz Highway.

In 2005, the state reduced the number of occupants to two and ridership spiked, but has peaked and the number of vehicles using the Zipper Lane so far this year look to be less than last, Morioka said.

The lane now carries about 3,800 cars every weekday from 5:30 to 8:30 a.m., up from about 2,300 cars in 1998. Once the new requirement goes into effect, the state expects to see about 3,500 cars in the lane.

"We will monitor it now and through the summer," Morioka said. "We want to give it time."