In a positive and anticipated development, construction of the rail transit project between Kapolei and Ala Moana has received federal approval to proceed without delay. The city should begin building the 20-mile rail line with confidence that much of the cost for the overall project will be paid with subsequent federal reimbursement. Putting brakes on the hugely needed project at any point in the months ahead would be foolish and wasteful.

U.S. Sen. Daniel Inouye announced on Monday that the Federal Transit Administration has issued a "letter of no prejudice" on the city’s plan, allowing the city to begin up to $184.7 million in heavy construction with intent of federal reimbursement.

The city can expect to obtain a final commitment of federal funding by October: $1.55 billion as the federal share of the $5.27 billion project, the local share coming from a half-percent excise tax surcharge on Oahu.

This advancement was anticipated following a meeting last month in Washington, D.C., between FTA Administrator Peter Rogoff, Honolulu Mayor Peter Carlisle and Don Horner of the Honolulu Authority for Rapid Transportation.

Rogoff said more than a year ago that the city had met early requirements "and we look forward to the day when Honolulu citizens can ride the rails in comfort, breathe clean air and avoid getting stuck in time-wasting traffic jams." That day is nearing, although still years away.

The city asked for the letter of no prejudice in December so it could proceed with construction this month. Without the FTA letter, the city would have faced a cost of $9 million for each month of delay in compensating companies that had mobilized their crews but were unable to begin construction work. Recent delays already have cost at least $15 million, and further setbacks could add significantly to the ultimate cost.

A federal lawsuit by opponents of the rail project will not stop the early construction; even a talked-about possible preliminary injunction will not be materializing to block the start of construction. However, if a federal judge were to permanently halt construction at some later date, the city would have to eliminate all it has accomplished. Such an outcome would be devastating, especially for families who bought homes in and around Kapolei in anticipation of the rail connection with downtown Honolulu.

If the anti-rail forces prevail, taxpayers still would have to pay for what has been spent on the project. New Jersey Gov. Chris Christie scrapped a commuter-rail tunnel project between New Jersey and New York City’s Penn Station in October 2010. As a result, the New Jersey transit took a $297 million loss for engineering and design work that had begun in 2009 and forfeited a $3 billion federal grant, the largest FTA grant ever made. A similar turnaround in Honolulu would be dreadful, not only financially but in commuters’ way of life.

Voters also should remember that a majority approved of this rail project via City Charter amendment in 2008.

"We have debated and discussed a rail transit plan for Oahu for decades," Inouye said in announcing the FTA commitment, "and I am very pleased that the administration is allowing the city to proceed with construction. Too many hard-working families on the west side of the island spend too much of their time stuck in traffic."

In the months ahead, commuters will see the project emerge in the form of an overhead guideway from eastern Kapolei, past the University of Hawaii’s new West Oahu campus and heading toward Waipahu.

Like a growing number of cities across the country, Honolulu should reap the benefits of rapid rail.