There’s been a new wave of criticism aimed at Honolulu’s $5.3 billion rail project, arising partly because the new Honolulu Authority for Rapid Transportation is getting under way and partly because of point-counterpoint commentary pieces that have run in these pages.

After volleys were exchanged and the dust settled, there seems to be reason for raised eyebrows and concern, but not for all-out panic. The basic case for the project remains intact; despite the flashing of caution lights, there seems little justification to switch them from yellow to red.

However, renewal of the debate is not entirely unhealthy. It’s important that public awareness and engagement be kept at an elevated level, especially while concerns about the principal contracts remain unresolved. Questions about the finances of Ansaldo Honolulu — the winning contractor to design, build and, at least initially, operate the system — arose after parent company Finmeccanica indicated plans to restructure or sell AnsaldoBreda, the partner set to deliver the rail cars.

Not surprisingly, heightened levels of taxpayers nervousness erupted. They rightly wondered: Just how robust was the vetting process?

Compounding the impulse for nail-biting, HART has just announced its intent to give former state Sen. Robert Bunda the last remaining post at the 10-member authority’s table. In its recommendation, besides citing Bunda’s experience with governmental and land-use proceedings, HART noted that he is "a long-standing and staunch supporter of the city’s rail project."

But what the authority needs most was not another cheerleader, but someone with more professional experience in urban or, ideally, transportation planning. When the Bunda recommendation is heard Sept. 16, the authority must make its case. There were 16 applicants, and the public deserves to know all the names and what other skill sets were available for hire. Given that the whole rationale for the semiautonomous HART was that it would diminish political influence on the project, the selection of a career politician will require some work to defend.

In the last week, Mayor Peter Carlisle, who recently had played a more low-profile part in the ongoing discussion, broke his silence and, in making the rounds, spoke with the Star-Advertiser editorial board. The outreach followed publication of an Aug. 21 commentary by a team of rail critics: Retired Judge Walter Heen, former Gov. Ben Cayetano, businessman Cliff Slater and law professor Randall Roth. They are plaintiffs in a lawsuit challenging the process by which the city chose elevated rail over alternatives that the suit contends would reduce traffic and protect the environment.

The city responded Aug. 28 with its own commentary. During his visit last week, Carlisle clearly was bristling about the allegations and took some gratuitous shots at the foursome (example: Cayetano lives in a fancy East Oahu ridge home and is unsympathetic to West Oahu traffic woes). Still, he and his staff did counter several of the critics’ points. Here are a few:

» The city has not changed its tune on the jobs rail would generate but has given consistent estimates: on average, 10,000 for each year of construction, with a peak annual job count of 17,000.

» The Federal Transit Administration supports its cost estimate from the project as $5.3 billion, not $7 billion. The project’s cost is $3.6 billion in today’s dollars, and that is $5.3 billion in year-of-expenditure dollars, which include inflation and interest.

» An at-grade rail system would not be a better alternative but would require more land excavation, cost more, and be prey to traffic delays and accidents.

The critics did score some hits, of course. For instance, the city could indeed do more to provide parking at more of the 21 stations, to encourage ridership. And directing affordable housing and other development at the rail stops won’t be a slam-dunk proposition.

But on the whole, the city makes a still-credible case that the elevated rail project, as proposed, would best meet Honolulu’s need for a reliable transit alternative to overcrowded freeways — and as important, boost construction and mitigate and direct Oahu’s expected population growth.

In the coming weeks, as HART revs up and various contract issues move toward resolution, it’s crucial that the rhetoric on both sides of the project remain factual and clear. Backsliding into defensiveness and emotionalism is unhelpful to the taxpayers who, now more than ever, need that clarity.