Commuters stuck in the D.C. region’s traffic feel utterly powerless. And usually they’re right to feel that way. The region does not have a strong lobby strictly for the benefit of commuters. That’s one curiosity about the turmoil over the cost estimates on the Dulles Metrorail project: Leaders involved say the cost of the project must come down for the sake of the Dulles Toll Road drivers.

Those drivers are going to bear the brunt of the cost for the second stage of the Metrorail extension, the part that will take the line to Dulles International Airport and out into Loudoun County. So it’s heartening to see so much concern about their well-being.

Of course, these are the same drivers whose commutes were made much worse recently by the work zone for the new lanes that will provide a faster ride for Capital Beltway drivers willing to pay tolls. So the Dulles Toll Road drivers have not exactly become a pampered class.

Also, their empowerment probably isn’t solely the result of their status as commuters. They also are potential voters in upcoming senatorial and presidential elections in which heavily populated Northern Virginia — and especially its outer suburbs — could tip the balance. In that environment, no politician wants to be on the wrong side of a debate over gas taxes or tolls.

The focus of the cost-cutting debate is the location of the Metrorail station at the airport. Should it be where it’s cheapest to build, or should it be where people are most likely to use it?

Peter M. Rogoff, head of the Federal Transit Administration, suggested to Metro Board members Thursday that the location of the airport station is of little consequence to flyers. Sure, they would want the station to be as convenient as possible to the terminal, he said.

But he implied that we really shouldn’t be that concerned about airport patrons, because the station will mostly be for airport workers, who apparently don’t care how far they have to walk to reach their jobs.

Rogoff and the U.S. Department of Transportation are in this to help. They’re providing a much-needed forum for getting all the interested parties together to reduce the escalating cost of the line’s second phase.

But in the context of a decade-long debate over whether we should spend more than $5 billion for a heavy rail line out to the airport, this argument about the airport workers vs. the passengers is a bit of a bait and switch.

Those who have paid attention to the debate about the transit plan are more likely to have heard this sales pitch: In the 21st Century, any world-class metropolitan area needs a rail line to connect air travelers with the central city.

We should care about the commute for airport workers to a major employer like the airport. If we cared that much about them, perhaps we should have protested more vigorously when Metro doubled the fare on the 5A airport bus to $6 last year.

The cost savings on putting the station where few air travelers would use it is huge. On Rogoff’s cost chart, building an aerial station by the North Garage would save $562 million. But at these prices, his argument that few air travelers will use the station comes perilously close to an argument for no station at all.

And it’s likely to come across that way to Dulles Toll Road drivers. You can make an argument to them that the Dulles line is worth the overall investment, because construction of parking garages at some stations will take some commuters off the toll road. But most of them have no reason at all to care about the placement of the airport station.