The Metropolitan Washington Airports Authority is now calling itself the champion of Dulles Toll Road commuters, who may end up paying $18 for a round trip on the toll road by 2023.

The authority, which enraged local and state officials when it voted to build an underground station at Washington Dulles International Airport in April even though it cost taxpayers an extra $330 million, now says it has done all it can to cut costs on the nearly $7 billion rail project and is begging state and federal governments for more money.

Authority board members said they are hoping for as much as $500 million from Virginia -- far exceeding the $150 million state officials offered to pay. MWAA also wants the federal government to lend it between $700 million and $1.2 billion on top of the multimillion-dollar federal loans Fairfax and Loudoun counties are seeking.

Without that extra state and federal money, authority members said, fees on the Dulles Toll Road would have to be raised even more than expected. Previous projections put the cost of a round trip on the toll road at $18 by 2023, with tolls going even higher later, though local authorities said further engineering studies could reduce those estimates.

What You Could Pay
Estimated one-way tolls for Dulles Toll Road if state and federal governments don't contribute additional funding for Dulles rail project
2012 $2.25
2013 $4.64
2018 $6.95
2023 $9.01
2028 $11.07
2033 $13.13
2038 $15.19
2043 $17.25
Source: Metropolitan Washington Airports Authority

"We are now in the position of being the defender of the toll payer," authority Chairman Charles Snelling said. "Toll road users need more help from the federal government."

Local officials said it's unlikely that the authority's new demands of state and federal governments could be met.

"That's as unrealistic as them getting [federal loans] for the full project. They're not dealing in reality," said Fairfax Supervisor Pat Herrity, R-Springfield.

Virginia lawmakers previously objected to giving any more money for the rail project unless the authority that's overseeing the construction drops its plans to have a union-friendly labor agreement with the project's contractor. Virginia is a right-to-work state, meaning workers can't be forced to join a union.

The authority's Dulles committee chairwoman, Mame Reilly, said MWAA would keep the union labor agreement though lawyers are reviewing it to ensure it's compliant with Virginia law.

Negotiators are still working out details of the funding for improvements Fairfax and Loudoun agreed to make and debating the labor agreement this month. They hope to have a revised deal hashed out by September or October, said Phil Sunderland, MWAA's general counsel.