Starting this morning, drivers headed diamondhead on the H-1 Freeway can expect to find a new lane from the Liliha on-ramp to the Pali Highway off-ramp after a night of work by crews from the state Department of Transportation.

State Transportation Director Rod Haraga said yesterday that crews were expected to complete the work overnight. He said studies show many of the drivers in the area enter the freeway on the Liliha on-ramp, then exit just one-quarter mile later, so squeezing in the fourth lane instead of a shoulder lane should ease a traffic bottleneck.

The change can be accomplished overnight, Haraga said, because it amounts to scraping off the old lanes and markers and painting in new ones. Haraga said the three existing lanes were 12 feet wide and the four new lanes will be 11 feet wide.

Haraga said the work was scheduled to be completed by 4 a.m., so that the new lane would be ready for morning rush hour. However, Haraga said, the new lane is likely to smooth traffic in the afternoon more than in the morning hours.

Sesnita Moepono, chairwoman of the Liliha/Pu'unui/ 'Alewa/Kamehameha Heights Neighborhood Board, said she thinks the change will be welcomed by those who live in the nearby communities and those driving through the area.

"That sounds like a great idea," said Moepono, who often has found herself using that short stretch of freeway to get from Liliha to downtown.

Haraga said the change should benefit drivers headed to the Windward side as well.

Moepono noted that the idea made so much sense to some people that they tried to do it without benefit of the new lane being built. "I've seen people drive on the shoulder and do that," she said, but added that while those drivers might be praised for creativity, it was a dangerous do-it-yourself practice.

Haraga said the work is being done by state crews — from design through construction — at a cost of about $25,000.

He said the change will allow drivers headed Windward to go directly from the on-ramp on through to the Pali off-ramp without having to merge onto the freeway.

Haraga said the new lane might save drivers up to 10 minutes of travel time, but its main benefit comes from simplifying the flow through that area.

"It's more of a practical matter of getting cars from here to there without interfering with the natural flow of freeway traffic," he said.

Because the new lane is a change for the area, Haraga said, "we're asking folks to drive carefully" while everyone gets used to the shift in traffic flow.

Haraga said the change has been discussed for years but required permission from federal transportation officials to narrow the width of the lanes.

"This is a project long in coming," said Haraga, adding that Gov. Linda Lingle's administration has worked to find creative solutions to ease traffic congestion. Even small changes, Haraga said, can save "a tremendous amount of time for drivers."

Reach Robbie Dingeman at rdingeman@honoluluadvertiser.com.