A New Emphasis on Rail to Dulles

"The choice was made here to use federal money to build the line," Millar said. "But that brings with it a very, very long and arduous planning process and a planning process where the parameters of how a project is judged changes over the 10 years it runs its course."

The rail project's high cost has led opponents to question whether it's worth it, especially when, they argue, rapid bus service would be much cheaper and equally effective.

"Studies looked at from various airports around the country show passengers do not use rail in high numbers," said Ken Reid, a leader of an anti-rail movement. "The problem is the airports authority has a very 1950s or '60s idea of what this will do for them."

The Dulles plan has also lagged because of uncertainty surrounding its funding and scope.

The financing plan calls for 50 percent to be paid by the federal government, 25 percent by the state and 25 percent by communities.

Cost concerns led planners to split the project into two phases, with a first phase running through the Tysons Corner complex of stores, offices and residences. There are no assurances that the second half -- extending the line through the airport -- will be funded.

The price of the first half of the project is about $300 million over budget. Also, the federal government has yet to commit to its share, and property owners along the second half of the route have not agreed to tax themselves to generate money for the local share.

The airports authority released a plan last week that aims to eliminate many of those concerns by taking over the Dulles Toll Road from the state government and using its revenue to fund Virginia's portion of the rail line as well as the state and federal share of the second phase.

Bennett has said rates on the road would rise "regularly" to keep pace with inflation and pay off bonds used to finance the project. Tolls now range from 50 to 75 cents.

The airports authority is in competition with several private proposals to operate the toll road, but the authority has some clout: It owns the land under the road.

A study of the proposed Dulles rail line estimated that 6 percent of airport users would ride it in 2015. Bennett said that would translate to about 2.4 million of the 40 million customers Dulles expects to serve in 10 years.

No airport in the country attracts more rail users than National, where about 3.2 million fliers, or 17.6 percent, come by Metro each year, airport officials said.

About 1.4 million people a year use rail to get to Baltimore-Washington International Thurgood Marshall Airport, about 60 percent on a light-rail line from Baltimore and the rest on an Amtrak link from Union Station in the District.

Bennett said he thinks that the estimates for Dulles are low and, regardless, that rail is about providing options.

"For an airport to be successful in the long term, it needs to have multimodal access, especially in a large metropolitan region such as we have," he said. "It's just not reasonable to expect and believe in the future that for everyone that wants to use Dulles Airport, the only way is by private automobile."