Rates on Dulles Toll Road will rise next year. (Jahi Chikwendiu/The Washington Post)

Effective on Jan. 1, the toll rates will go up by a quarter.

For two-axle vehicles the main plaza rates will now be $1.50; for 3-axle they will be $1.75 and for 4-axle they will be $2. Prices at the ramps will not change.

On Tuesday night, representatives from the Airports Authority are holding a meeting at South Lakes High School in Reston to give results of the impact of the toll increase in 2011 and provide information on upcoming toll rises for 2012. They also will give an update on improvements to the Toll Road and the financing of the Dulles Metrorail project.

The first phase of the rail line is currently under construction and is expected to be completed in late 2012. The second part of the rail line, which will run from Reston to Dulles International Airport and to Loudoun County is expected to cost $2.8 billion.

More than half of the money to pay for phase two of the new Dulles line — which is being called the Silver Line — will come from users of the Dulles Toll Road.

Loudoun and Fairfax counties, along with the Washington Metropolitan Airports Authority (MWAA), and Virginia, plus some federal grants will help pay for the rest.

Tuesday night’s meeting will be held from 5 p.m. to 8 p.m. in the cafeteria at South Lakes High School, 11400 South Lakes Drive, Reston.

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