There is no threat to the construction of a rail line out to Dulles International Airport. It’s going to get built. The key decisions to do this were made years ago. Today’s politicians are haggling over the details.

The decisions that got us to this point included choosing a a heavy rail line over bus rapid transit, choosing a route through Tysons Corner rather than taking a straight shot at the airport and choosing to put the airports authority in charge of the construction.

If politicians didn’t want the airports authority to be the decision-maker on the location of the airport station, they shouldn’t have put the airports authority in charge of building the railroad.

Really, which station did they think the airports authority would care about? The one near the Capital One building? The one near Tysons II? No, the people in charge of the airport care about the one that airport patrons will use.

And since we’re on a course to invest more than $5 billion in taxpayer and toll-payer money in this railroad, we also should care about putting the station close to the potential riders.

This isn’t going to be a bullet train to downtown D.C. At Dulles, people who got there traveling more than 500 mph are going to step aboard commuter trains that average 33 mph and stops four times in Tysons Corner.

The Dulles Metrorail project is a hybrid. It’s partly about making sense out of that space station we call Tysons Corner. It can’t be the 21st Century economic hub that people envision if everyone has to drive in and out of the place.

But Dulles Metrorail is also about Dulles. To succeed, the airport transit system has to be competitive with other ways of getting to and from the airport. It has to be easy to reach when you pluck your bags off the luggage carousel and look for the exit.

Individual politicians may see some political interest in sticking it to the airports authority over the station’s location. But the D.C. region’s interest is in finding a way to put the station within a few football fields of the terminal while keeping the cost as low as possible.

To achieve this, the airport leaders are going to have to work harder. You can tell Dulles Toll Road users that the rail line will divert some of today’s drivers to transit and leave the lanes less congested. But there’s no way you can make them care as commuters about where the airport station is located.

But the politicians who have been bashing the airports authority will have to stop pandering and join in some serious discussions about revenues and costs. The problem isn’t the location of the station. The problem is the cost of the project.

Instead of shaking down the Toll Road users, could there be another revenue source? Could there be a surcharge on using the airport station? Metro already crossed that threshold last year by creating a financing plan for station improvements that allows for a surcharge on riders entering or exiting a particular station.

Wouldn’t it make sense to divert some of the financial burden from commuters who pay every day onto people who use the airport occasionally but benefit directly from the convenient location of the station?

My hope is that all parties will focus on the real goal in a forum provided by the U.S. Department of Transportation. I’ve heard Transportation Secretary Ray LaHood speak about this issue twice in May.

LaHood notes that the federal government has $900 million invested in the project. He said he wants a solution that “respects the idea that we don’t have a bottomless pit of money.” But he also pledged that the dispute over the station will not derail the goal of bringing the new transit line across Northern Virginia and making the airport connection.

“It’s a very important project,” LaHood said, making a statement I wish other leaders would echo. The first phase of the rail line is more than a third built. If this project were halted, what would they tell the people of Tysons and McLean who have endured the construction phase? “Sorry about your neighborhood, man. You want us to spray paint those big railroad piers before we leave?”