In a significant change to the much-anticipated rollout of the Honolulu rail line, the city is now planning to open new segments of rail in 2020 and in 2023 before finally opening the entire 20-mile line in 2025.

A rail recovery plan submitted to the Federal Transit Administration last fall envisioned just one interim opening followed by the opening of the full rail line, but Honolulu Authority for Rapid Transportation Executive Director Andrew Robbins said the city is now planning for a second interim opening.

The first segment of the $9.2 billion project to open will be the 11-mile stretch from East Kapolei to Aloha Stadium, which includes nine stations and is scheduled to begin service to the public in December 2020.

The next 5-mile segment, to Middle Street, including four stations, would open in late 2023, Robbins said, and the city plans to open the rest of the line to Ala Moana Center in December 2025.

At least, that’s the plan. The project has been delayed repeatedly, development is running six years behind schedule and a consultant for the FTA has concluded there is only a 65% chance the entire rail line will actually open in September 2026.

Robbins said HART will be turning over segments of the rail line to the city as they are completed, and construction of the stretch from the stadium to Middle Street is scheduled to be “substantially completed” in 2021.

HART needs time to do extensive testing of the new segment, but in late 2022 or early 2023, it will be finished and ready to open to the public, Robbins said.

“I think there was a realization that as long the asset is completed and it’s there, we should consider putting it into service,” Robbins told the HART board Thursday.

Wes Frysztacki, director of the city Department of Transportation Services, said that if the city had only one interim opening, “for several years we would have a completed product just sitting there, and the thought was, Why?”

Frysztacki said the interim openings will give rail personnel a great deal of experience in operations, security and maintenance of the system that will prepare them for the opening of the full rail line scheduled for 2025.

“We’ll have a large staff that is ready to operate 21 stations, so it’s not just offering passenger service, but it’s also gaining all that staffing that’s necessary to operate a good system, on time, with quality operations,” he said.

The tentative plan is to run four-car trains every 10 minutes on the first segment of rail, but Robbins said he is uncertain whether the same schedule will hold for the second segment. When the rail line is completed, the trains will run every five minutes during peak hours, he said.

HART staff said there are no firm ridership projections for the interim openings yet. The city is projecting 119,000 weekday boardings in 2030 after the entire rail line opens.