Work is underway to improve Pali Highway, resulting in barriers, lane closures and, by the middle of next month, complete overnight closures for three long-anticipated projects that are expected to last two years.

The state Department of Transportation held a blessing ceremony Wednesday for the $64 million first phase of the project, which includes the installation of LED light fixtures from Vineyard Boulevard to Castle Junction and resurfacing from Waokanaka Street to Castle Junction, estimated to be completed by next winter.

“This is work that’s been long anticipated,” said Ed Sniffen, state deputy director for highways. “The condition of the pavement has been deteriorating over time.”

The installation of 450 LEDs is expected to save the state about $99,000 per year in energy costs, while the roads will be resurfaced with a typical asphalt mix to smooth out the patchwork of pavement resulting from spot repairs over the years.

The city, meanwhile, is also planning a major city sewer system upgrade — the Dowsett Highlands Sewer Relief project — which will include part of the Pali from the Wyllie Street intersection to Nuuanu Pali Drive. The sewer project is scheduled to begin in June, according to palisewer.org, and will happen at the same time as the lighting replacement work.

In response to public complaints, the state had been looking to make improvements to the Pali since 2015, according to Sniffen, but Likelike Highway was also in need of resurfacing. Since the Likelike project was shorter, the state opted to work on it first so as not to affect two major routes connecting the Windward side to downtown Honolulu.

The Likelike project is expected to wrap up this spring.

Already, motorists may have noticed re-striping of the lanes and barriers put up along Pali Highway in the Nuuanu area to prepare for the repaving of the grassy medians. The medians will eventually be paved, and traffic lanes will shift closer toward them, while a portion of the right shoulder will be blocked off for electrical work.

In an effort to minimize the impact on traffic, the state Transportation Department plans to keep three lanes open during the peak travel hours of 5 to 9 a.m. town-bound and from 3 to 6:45 p.m. Kailua-bound on weekdays, not including holidays.

Drivers should be aware that lanes will be narrowed and shifted to maintain the three open lanes.

Beginning mid-February, however, drivers on the Windward side will have to find alternative routes to get into town at night.

Full overnight lane closures are planned for all town-bound lanes of Pali Highway from 8:30 p.m. to 5 a.m. every night except Friday and Saturday from Castle Junction (Kamehameha Highway intersection) to Waokanaka Street. During those hours the left lane of the highway in the Kailua-bound direction will also be closed.

To be most efficient, Sniffen said, most paving work will be done at night, requiring the closures, which are expected until March 2019.

Motorists can use Likelike Highway, the H-3 freeway or Kalanianaole Highway as alternate routes during the full closures.

Danielle Scherman, a real estate agent from Kailua, uses the Pali often.

“I try to avoid rush hour,” she said. “I’m not so concerned about it because I have a flexible schedule.”

The nighttime closures will present a challenge, she said, but she hopes to get plenty of advance notice so she can plan for them and take alternative routes.

“I guess they have to do it,” she said. “As long as everyone’s fully aware.”

Peter Anderson, owner of Morning Brew Coffee House and Bistro, which is in Kailua and Kakaako, said it means he may have to drive along Kalanianaole Highway through Waimanalo to travel between both businesses.

His cafes close at 6 p.m., so the overnight closures will not affect him so much, but he does worry about whether tourists will make the trip to Kailua if the Pali is difficult to travel.

Sniffen estimated about 40,000 to 50,000 vehicles use the Pali Highway corridor, a primary route for Windward drivers to get to town, per day.

A second phase of resurfacing work on Pali Highway, from Vineyard Boulevard to Waokanaka Street, is expected to begin after the city completes its sewer project, in summer 2019, with completion in winter 2020.

During that time, Sniffen said the state also plans to keep three lanes open in both directions during peak travel hours.

Electronic message boards will be posted, and special-duty police officers will assist with traffic control. Construction updates will be available at palihighway.org, along with a 24/7 hotline at 945-1111.