Mayor Kirk Caldwell says the city is “not yet confident” the first 11-mile segment of the Honolulu rail line will open at the end of this year, and told the Honolulu Authority for Rapid Transportation that it should stop promising the public that rail will open even earlier.

HART Executive Director Andrew Robbins said at a news conference early this month that the rail line would be ready for the public to ride by October, but both Caldwell and the state Department of Transportation are warning they are not prepared to open the system by then.

Caldwell was in Washington, D.C., last week on a trip that included a sit-down meeting with top officials in the Federal Transit Administration, and he returned to Honolulu to draft a letter urging the rail authority board to “better understand and monitor” some critical issues.

“The board should require HART to cease making promises to the public of an artificial starting date of rail service,” Caldwell said in the letter dated Wednesday, referring to Robbins’ proposal to launch rail in October.

“Internally, the city’s target date is December 2020, but the city is not yet confident in the ability to open by that date,” Caldwell wrote.

He noted that while HART is responsible for building the 20-mile rail line from East Kapolei to Ala Moana Center, it is the city Department of Transportation Serv­ices that must operate the system, and “the city has not committed to a date for the opening of service.”

Announcing a partial opening of rail in October generated positive news coverage for the rail project, Caldwell told the rail board Thursday, “but if we don’t deliver on the promises made, what remaining trust we have is going to evaporate.”

“At this point, I wouldn’t promise anything,” he told the board. “I would just make sure I tried to deliver everything as quickly as possible.”

Caldwell also reminded the rail board that while the city intends to open the entire 20-mile rail line in December 2025, the FTA has said it calculates there is only a 65% probability that the rail line will open by September 2026.

“That additional time is partly why they believe the City and County of Honolulu will have to come up with additional money on top of what’s already been provided through these different funding mechanisms, which I hope doesn’t happen,” Caldwell said. “I will not be mayor, but I do not want to see the taxpayers be burdened with that.”

Caldwell clarified in an interview after he left the meeting that the FTA is not predicting the cost of rail will increase beyond the current $9.2 billion budget for the project, but is warning that the cost of rail could increase again if there are further delays.

The rail project is already billions of dollars over its original budget approved by the FTA in 2012, and is running six years behind schedule.

Caldwell described the meeting with FTA last week as “sobering,” and urged the rail board to focus less attention on the interim opening and pay closer attention to keeping to the deadline of December 2025 for opening the entire 20-mile rail line.

Caldwell said recent “slippage” in the rail schedule has reduced the “schedule contingency” — that is, the cushion in the schedule — from almost a year to only about 100 days for what the FTA believes will be six years of construction.

“Now, is that a realistic cushion, or not? The FTA talked about that. It should be a major concern for all of us, watching that cushion,” Caldwell said. “It could slip more, so it’s extremely important to make sure that there’s no more delay, because that cushion could slip away.”

In a related development, state Department of Transportation Director Jade Butay last week wrote to Robbins and city Department of Transportation Serv­ices Director Wes Frysztacki warning there does not appear to be any extra time or “float” in the rail schedule between now and the planned December opening.

The Butay letter strongly suggests the city will not be ready for an October opening, and Butay sent copies to more than a dozen city, state and federal officials. State DOT has responsibility for the safety of rail as the official State Safety Oversight Agency for the system.

Butay asked in the letter for clarification on exactly when rail will open to the public, and noted that his rail safety office “has documented concerns with DTS’ readiness in every Site Visit Report issued from 2018 to present.”

“If HART and DTS aim to carry any members of the public on the rail system prior to December 20, 2020, then project documents must clearly reflect an achievable plan and schedule to reach that goal,” Butay wrote.

After Caldwell left the board meeting Thursday morning, Robbins acknowledged that the date of any interim opening for rail is up to the city, which is tasked with operating the new system.

The official date for the interim opening is Dec. 20, and “if we actually do complete our activities a little bit sooner — I’m talking 40 or 50 days ahead — maybe the city would see fit to have some kind of demonstration service a little bit earlier” between East Kapolei and Aloha Stadium, Robbins said.

For his part, Caldwell is also warning of ominous signs that could signal even more problems for the city’s $9.2 billion rail project, such as delays in construction, permitting and the procurement of a huge new contract.

Caldwell noted the date to award a huge contract for a public-private partnership to complete the rail system has been delayed four times, and the city has not yet gained access to some properties where utility relocation construction work is supposed to begin in the near future.

HART also needs to finalize a critically important traffic management plan before the city can issue permits for day and night construction work relocating utilities in the urban center and along the Dillingham Boulevard corridor.

The city expected HART to submit that traffic plan in November, and then in December, but the plan “to our knowledge has not yet been submitted,” Caldwell wrote in his letter to HART.

HART spokesman Bill Brennan told the Honolulu Star-Advertiser in a text Jan. 6 that the traffic management plan for Dillingham was submitted to the city in December, but clarified Thursday what was actually submitted late last year was a draft memorandum modifying an existing HART traffic plan.

The city then responded with comments about the draft memo, and it is now up to HART to respond to the city’s observations and concerns about the draft traffic plan, Brennan said. Robbins said he expects that by the end of February, HART and the city will have made enough progress on the traffic plan that the city can issue the necessary permits.