Toll road drivers face increases on both the Dulles Greenway and the Dulles Toll Road Jan. 1.

The Toll Road’s main plaza rate will increase by 25¢ to $1.50, while the rates at on/off ramps will remain 75¢. The Greenway rates will increase by 30¢ during regular hours and during rush hour to $4 and $4.80, respectively (Greenway drivers continuing on to the Toll Road pay an additional 75¢ to enter the that road; tolls for those drivers will amount to $4.75 and $5.55, respectively).

For Ashburn commuters heading to Arlington or Washington, DC, via those roads, that means a double hit on daily travel expenses totaling about 55¢ per day. Throughout an entire year, that’s a fee increase in the range of $140.

The steady toll increases drivers in Northern Virginia have watched over the years often spark anger – for some because they had hoped the Toll Road fares would go away long ago, and for others because the private owner of the Greenway earns state-protected profits from its tolls.

Tolls along the Toll Road pay for maintenance and operation of that public road and help fund the Dulles Corridor Metrorail Project. The permitted use of toll money by the Metropolitan Washington Airports Authority is contained in agreements with the Commonwealth of Virginia and local governments in Northern Virginia. Under its agreement with the Commonwealth of Virginia, the Airports Authority assumed the responsibility to operate and maintain the Dulles Toll Road for a 50-year period that began in 2008.

Next week’s increase on that road was approved in 2009 as part of a three-year schedule for toll rates. After the Jan. 1 increase, MWAA’s Board of Directors must hold public hearing before considering further increases.

Greenway tolls pay for operation and maintenance of that private road, but the operator – Australia-based Macquarie Group – also has the right to earn a profit from managing the road that was written into state law when the road was initially authorized in the early 1990s. Macquarie was not the original owner, but eventually purchased the rights to the road. Control of the road was granted through a 50-year concession, after which it reverts back to the state.

The Greenway is the sixth-largest contributor of real estate taxes in Loudoun County. The Greenway is financed through the private bond market and 69 percent of all tolls go to debt service, with an additional 28 percent set aside for items such as police service, operations and maintenance, E-Z Pass fees, MWAA fees, property taxes and insurance. Beginning on Jan. 1, 2013, the Greenway’s tolls will be tied to the Consumer Price Index, rather than the rate schedule in effect until then.

Vehicles with more than two axles pay higher tolls on both roads.