The state plans to build a $3.5 million, quarter-mile-long retaining wall next year to stabilize a shifting section of Likelike Highway, which Kalihi Valley residents first started complaining about three years ago.

Late this year, the state will repave a portion of the roadway to stop water from sinking into cracks and potentially moving soil. The repaving was first scheduled for January, but back-to-back weather problems and an asphalt shortage delayed the project.

"We had three months of rain and we had two months of an asphalt shortage," said Scott Ishikawa, state Transportation Department spokesman. "This asphalt shortage backed things up."

For some Kalihi Valley residents, work to stabilize the roadway is overdue.

They contend that the repaving and retaining wall projects should have been a higher priority for the state, and some worry about the possibility of a landslide affecting some 40 homes downhill of the slipping land.

"We're concerned," said Bill Woods, chairman of the Kalihi Valley Neighborhood Board and a candidate for the state House District 30 seat. "It started in 2003. ... And every time we go out there and look at it, we see the cracks are different. They're longer."

But Ishikawa said the slipping section poses no imminent danger.

A 2004 study concluded that the slipping would become a big concern only if the state failed to do anything over the next few years.

"If you don't deal with it, we're going to have an erosion problem," Ishikawa said. "The retaining wall is the long-term fix."

The slipping portion of the roadway is under the right-hand, Kane'ohe-bound lane, above Kupehau Slopes Park. State crews will repave the highway from about the start of the park to Emmeline Place.

Ishikawa said the project is now at the top of a list of roads to be repaved and likely will be completed within the next two months.

Funds for the retaining wall are in the upcoming Transportation Department budget, and planners are working to design the structure.

But residents say they're concerned the shifting soil under Likelike Highway near Emmeline Place is not an isolated problem and are urging the state to do more work to monitor the roadway.

Ishikawa said crews inspected other parts of the highway and found no additional problem.

He noted that a sinkhole on Likelike Highway in February 2004, which sent mud rushing into Kalihi Valley homes in a subsequent landslide, was unrelated to the Kupehau Slopes problem. In that case, heavy rains blocked a drainage pipe, causing the line to break and sending debris into homes positioned below the highway.

As the state plans to fix the sinking section of the roadway, crews are finishing up a two-year project to revamp the Wilson Tunnel.

Before the end of the year, workers will install flashing reflectors on the ground in the Kane'ohe-bound lanes of the tunnel. The lights will better prepare drivers for the downhill descent out of the tunnel. Next year, a 500-foot portion of roadway heading into the tunnel from Kalihi Valley will be repaved, Ishikawa said.

Reach Mary Vorsino at mvorsino@honoluluadvertiser.com.