Starting the morning of July 8, the minimum ridership requirement to drive on the H-1 ZipperLane and the Nimitz Highway contraflow lane will be raised to three people per vehicle instead of two.

The three-person ridership requirement is intended to encourage more commuters to carpool in an effort to relieve traffic congestion on O'ahu, the State Department of Transportation announced today.

"As more people choose to carpool, it is important to provide them with incentives to continue to do so," state DOT director Brennon Morioko said in a released statement.

Morioko said the minimum requirement was increased to put more people in fewer cars, reducing the drive time and helping save money on gas.

The new hours go into effect 5:30 to 8:30 a.m. on weekdays, except on state holidays.

Initially, the minimum requirement to ride the ZipperLane in was three when it was introduced in 1998, but the requirement was reduced to two persons per vehicle in the summer of 2005.

DOT officials said the reduction has resulted in increased congestion in the ZipperLane, providing minimal benefit to carpoolers.

Motorcycles will still be allowed to used the ZipperLane and Nimitz Highway contraflow lane.