The planners of the Oahu rail system are looking ahead to the day when a partial opening of the service will give riders a chance to acclimate to rail, and give the operators a means to work out the bugs.

Although not required under the federal grant for the rail system, a partial opening would be worthwhile — if only the project could move in that direction with fewer fits and starts.

Future riders of the Honolulu rail system also need to have confidence that the officials directing its completion are all on the same page about the process, or at least communicating more clearly about it.

Instead, there’s breakdown, the public wondering and worrying where things are headed.

On Thursday, City Council Chairman Ernie Martin called on the Honolulu Authority for Rapid Transportation (HART) board chairman and chief executive officer to resign, pointing to anticipated cost increases pegged to power-line clearances that he said should have been headed off.

In an exchange fraught with political tension — Martin is contemplating a run for mayor — he urged Mayor Kirk Caldwell to join in the call.

This is just the latest fault line in a project whose support is fragmenting, just as HART, the semiautonomous agency overseeing construction, confronts the most challenging segments of the line.

A recent round of upheaval started over recent indications from HART that it has returned to its original proposal to start the partial service between East Kapolei and the Aloha Stadium station.

Months earlier, HART had considered holding off on the partial service until it could get riders to the Middle Street Station.

Reverting to the original Aloha Stadium plan is less than optimal. Disembarking from the train at Middle Street would allow for a much better-supported transition. Middle Street is already a major bus hub, so commuters could more smoothly complete their journey through this stop.

The Aloha Stadium stop is itself a less practical end-point; other than on game day, there’s not much within easy reach.

So the city and HART must work together to redirect additional key bus routes to make stops there, creating a mini-hub for the area, including circulator shuttles for nearby destinations such as Pearl Harbor.

Even if the switch back to Aloha Stadium is not ideal, the reason for it was defensible. The stadium stop represents the last of the first nine stations, Phase 1 in the project.

The Middle Street station is part of the 12-station Phase 2, but it’s the last in a grouping that now is not expected to be complete until only months before the entire line is ready to open.

The contracts for this group of four stations — Pearl Harbor, Airport, Lagoon Drive and Middle Street — and for the remaining eight to the Ala Moana Center end terminus, are expected to be complex, with work on the segments overlapping.

That complexity, given the hot construction market, is anticipated to increase the already skyrocketing costs. HART officials acknowledged new misgivings that the recently approved extension of the funding mechanism — Oahu’s 0.5 percent general excise tax surcharge — would cover the bills.

HART spokesman Bill Brennan said the agency is coordinating with the city on making the partial rail segment practical, with bus connections and a park-and-ride lot.

But prospects for such coordinated planning and rosy outcome are quickly receding amid all the conflict.

More of that lies ahead. Whether the city or HART takes charge of rail operations is at the center of competing City Charter amendment proposals; the coming debates on rail governance will put this clash on prominent display.

HART officials insist that they have kept the city in the loop. But Mike Formby, director of the city Department of Transportation Services, maintained in an interview with the Star-Advertiser that he didn’t learn of the change in plans over the Aloha Stadium opening until reading about it in the paper.

Reports of this dysfunction just adds to the strain taxpayers feel right now, and it’s the last thing they need. The price tag on the state’s largest public works project is past the $6 billion mark and rising, with the most complicated part of the work still looming.

What people need to see and hear is that those at the top are collaborating. But the noise coming through now conveys precisely the opposite.