Now that voters have flashed a green light for the city's steel-on-steel rail project, elected leaders must work to get the most for the more than $4 billion it will cost.

The best way to achieve that has always been routing the rail close to Pearl Harbor and, in particular, the Honolulu International Airport. But the City Council was unable to muster enough votes to approve the project, unless an alternative route through Salt Lake — City Councilman Romy Cachola's district — was crafted, winning his vote.

Fortunately, the administration had the consultants preparing the draft environmental impact statement study both routes, and now the council seems positioned to switch to the airport route.

Councilman Charles Djou, long an opponent of the rail project, said this week he's accepting the voters' verdict to move forward with the project. He now advocates that the council revert to the airport alignment — and he's right. His vote would produce the majority needed to make the switch; the council should approve the amendment soon, to minimize further delays.

In addition, there's the added cost of the longer airport route, an estimated $200 million. The state has been keeping 10 percent of the city's transit tax for administration; clearly, the tax collection is now set up and such a fee is not needed. The Legislature should let the city use that money for the increased construction cost.

Among the advantages of the route cited in the EIS:

• Bringing the train to town via Pearl Harbor and the airport would affect 5 percent fewer properties than on the Salt Lake route, meaning less cost and disruption arising from land acquisitions.

• The city anticipates fewer encounters with burials along the airport route, further reducing potential delays.

• The EIS includes a cost-benefit analysis that shows the added cost will pay off in increased ridership — 7,000 more daily passengers than for the Salt Lake route.

• Finally, there's more room for planned development around the transit stops along that stretch of Kamehameha Highway, which will yield a greater boost to the economy and increased capacity for affordable housing.

The council will need to see that the Pearl Harbor National Historic Landmark is protected in the buildout. But, on balance, the realignment offers a way to improve how this critical project serves the public interest. Council members must not pass up that chance.