HONOLULU -- Fewer drivers took the zipper lane on Tuesday morning on this first day of the Department of Transportation's new rule that cars must have at least three people instead of two.

"We didn't expect the change to happen overnight, but we do hope drivers as they see incentives that they offer that they will try to get three persons," DOT spokeswoman Tammy Mori said.

There were no major problems during the morning rush-hour traffic. It did appear that more cars filled the regular lanes than usual.

Some drivers said the change will create more traffic congestion, but DOT officials have said it is trying to shorten commute times and reduce the number of cars on the road.

The big test will come in the fall when public school and the University of Hawaii students go back into session.