The Honolulu Authority for Rapid Transportation on Thursday announced a $1.66 billion contract award to Los Angeles-based Tutor Perini Corp. to design and build Skyline’s last 3-mile segment to Kakaako.

The City Center Guideway and Stations contract will include design and construction of six rail stations and miles of elevated rail guideway beginning east of the Middle Street Transit Center station.

The route will end at the proposed Civic Center station, east of the intersection at Halekauwila and South streets, HART said.

The contract is expected to be executed in mid-­September.

In the past, HART said the estimated cost to build the CCGS project was $1.3 billion.

HART Executive Director and CEO Lori Kahikina said she did not know why Tutor Perini’s bid increased by about $360 million over what HART had estimated.

“No, I don’t know what their costs are, if they had any risks built into that,” she said. “I can only assume the climate that we’re in (is) very competitive, especially here in Hawaii — trying to get resources, whether it’s staffing or subcontractors or material, supply-chain issues.”

According to the rail agency, the project’s design will begin immediately after contract execution, while the start of construction is estimated in the second half of 2025.

Construction of this segment of Honolulu’s nearly $10 billion, 19-mile fixed-rail system will be completed in 2030.

“This is another huge milestone for our rail project,” Kahikina said Thursday in a written statement. “This is the largest single contract of the entire project and sets the course for completing the project through downtown Honolulu. We are excited to begin work with Tutor Perini to make this happen.”

A civil building and specialty construction company, Tutor Perini offers diversified general contracting and design-build serv­ices to private clients and public agencies throughout the world, HART said.

“Tutor Perini is proud and excited to be a part of this transformational project in Honolulu,” Ronald N. Tutor, the firm’s chair and CEO, said in a written statement. “We look forward to partnering with HART to see this project through to its successful conclusion.”

By phone, Kahikina told the Honolulu Star-Advertiser that she’s “had no experience” working with the California construction firm. But she said, “I think we can learn a lot from them. They do this all over the place; they can give us suggestions on how to do things better.”

And she noted, Tutor Perini was the second of two companies vying for this contract. The other bidder, City Center Builders Joint Venture (Dragados-Hawaiian Dredging), dropped out early on during the agency’s procurement process.

“In phase two there was only one offer,” she added.

Meantime, HART’s award of the anticipated CCGS contract is expected to trigger release of the next $250 million in federal funding to HART under the amended full-funding grant agreement, which was executed Feb. 2.

The original FFGA, signed in 2012, provided a grant of $1.55 billion for the Honolulu rail project.

HART previously received about $931 million under this grant, the agency states.

“Our funding is still the full-funding grant agreement, the $1.55 billion,” Kahi­kina said, noting rail construction money is also gleaned from the state’s general excise tax, transient accommodation tax as well as the city’s own TAT, which the City Council adopted in 2021. “That’s 100% where our funding comes from.”

Previously, the rail agency also claimed work would end by 2031.

“What we’ve been saying publicly is to open the last segment in 2031, but these are the infrastructure guys — the contractor — that need to be done by 2030 so that Hitachi, the core systems contractor, can come after … and they have to do all of their cabling, communications, testing (of the driverless trains),” Kahikina said. “So we budget about a year (to) a year and a half for all of that to be done, before handing it over to the (city Department of Transportation Services) for opening.”

HART board member Natalie Iwasa told the Star-­Advertiser she was pleased to hear the project was advancing.

“It’s good, but I temper that with my concern about the money, the contract awarding anyway,” she said. “But basically, I think it’s good that it came in within the funding that we currently have.”

A certified fraud examiner who’s consistently raised concerns over funding transparency related to city rail, Iwasa speculated the higher cost of this latest HART contract might relate to the months-long delay by some on the board of directors to consider renewing Kahikina’s $275,000 annual contract beyond Dec. 31.

On June 28, HART’s board voted to provisionally grant its CEO a new multiyear contract, with a minimum of three years, subject to terms and conditions to be negotiated, including her future salary.

Kahikina’s next contract, if adopted, would start Jan. 1.

“So when contractors are looking at that kind of thing, when they’re not sure who they’re going to be working with as the main leader (or) management person, then I would think they would have questions about what’s going to happen during the build-out of the project,” Iwasa said. “And we don’t know whether they put in a cushion or not, but it seems possible because the amount is higher than what was budgeted.”