Dulles Toll Road officials are eager to talk about an equipment upgrade that will bring the more than 30-year-old toll collection system into the modern age. The new system will allow drivers to pay by credit card and offer a self-service option for those who don’t have an E-ZPass transponder.

“The current technology of the road is very dated,” said Margaret E. McKeough, chief operating officer for the Metropolitan Washington Airports Authority, which manages the toll road. “This is a project that will make sure we keep stable and current the technology that’s supporting the toll road operation.”

What McKeough and others are reluctant to tout, however, is how the $23.4 million upgrade will give the system the ability to charge variable tolls — such as changing prices based on the time or day or amount of traffic.

Similar systems are in place throughout Northern Virginia, including the interstates 495, 95 and 66 Express Lanes. The most recent example is I-66 inside the Capital Beltway, where solo weekday rush-hour drivers traveling in the peak direction pay tolls based on traffic and demand.

Officials at the Virginia Department of Transportation, which manages the 66 Express Lanes, said the goal is to better manage traffic and encourage commuters to use other options, such as carpooling and public transit. The program, however, has generated criticism in part because tolls have topped $47 for a single 10-mile, one-way trip.

McKeough emphasized that no decision has been made on whether MWAA would move to a congestion-based pricing system.

“That is a policy question,” she said. “And I am here to talk about construction.”

MWAA board chairman Warner Session did not respond to requests for comment about the project or whether the panel was considering variable tolls.

The MWAA took responsibility for overseeing construction of the Metro Silver Line extension from the state of Virginia in 2006. As part of the deal, which officials said would save money and speed construction, MWAA also assumed control of the Dulles Toll Road and was given authority to raise tolls on the 14-mile roadway.

In MWAA’s request for proposals for the toll system upgrade, issued in March 2016, officials outlined the requirements that would allow a new tolling structure.

The document specifies that the system must have the ability to “implement one or more alternative toll rate structures and pricing schemes in the future.”

“These new alternatives may be implemented to support such aspects as congestion pricing, point-to-point or distance based tolling,” it says. In addition, the document says the system also should be designed to allow for dynamic pricing — which allows toll rates to be adjusted in real time.

MWAA awarded the contract to TransCore, the same Nashville-based company that is involved in the 66 Express Lanes. In addition, TransCore also has a $20 million, five-year contract to operate high-occupancy toll (HOT) lanes in Norfolk and was selected to modernize the toll collection system in Richmond. The company has been in business for more than 80 years.

Virginia is at the forefront of a growing number of states turning to toll roads as a way to manage traffic flow by encouraging drivers to choose carpooling and other options. In addition, toll revenue can be used to pay for other transportation projects.

Virginia, for example, envisions a network of more than 90 miles of HOT lanes in Northern Virginia by 2022.

No one wants to pay higher tolls, but increases on the Dulles Toll Road are a particularly sensitive subject, in part because toll revenue is being used to pay for construction of the Silver Line — a plan that some motorists and elected officials continue to oppose.

“Users of the toll road are people who do not take the Silver Line,” state Sen. Richard H. Black (R-Loudoun) said. “They don’t use it and they don’t get any benefit from it, yet they are the people who pay to make it go. I just have some problems with that.”

The federal government, MWAA, the state of Virginia, and Fairfax and Loudoun counties each pay a set percentage of the cost of the $5.8 billion rail project, but toll road users are the most vulnerable because the amount they contribute to the project is not capped. As project costs have risen, so too has the share that comes from toll road users. In 2004, tolls were expected to cover about 25 percent of the cost of the 23.1-mile rail line, but delays and cost overruns have pushed their share to nearly half of the project’s cost.

The first phase of the Silver Line opened in 2014; the second phase is expected to open to passengers in 2020.

Tolls were increased five times between 2010 and 2014 before stabilizing, after Virginia contributed $150 million to the project’s second phase, which will extend Metro to Washington Dulles International Airport and into Loudoun County.

Since 2014, the toll has been $3.50 — $2.50 at the main toll plaza and $1 at on/off ramps, but rates are expected to increase over the next 25 years.

The next projected toll increase — to $4.75 — for the main toll plaza and one ramp transaction — is scheduled for January 2019. By 2043, the rate could increase to $11.25; by 2048, the final year tolls are projected to rise under the current schedule, the rate would be $12.50, according to budget documents provided by MWAA. Once the Silver Line debt is paid for, revenue will continue to pay for operating and maintaining the toll road until 2058 when oversight is handed back to the Virginia Transportation Department.

Board documents about the modernization project also raise the possibility of different pricing structures for motorists who use E-ZPass vs. those who pay cash.

MWAA has been pushing drivers to use the electronic payment system because it reduces the need for toll booth staff and improves traffic flow. In 2017, about 88 percent of toll road users paid via E-ZPass vs. 12 percent who paid cash.

McKeough said the toll system upgrades will benefit drivers whether they pay with E-ZPass or cash.

According to a presentation prepared for the board, construction on the new toll facilities is expected to begin this spring and will involve some lane closures. But officials said that at least two full service lanes in each direction at the mainline toll plaza will be open at all times. The system is expected to be fully operational by early 2019.

“It’s probably the most controversial road in the Washington-metro area,” said John Townsend, spokesman for AAA-Mid Atlantic. “Anything done to change the nature of tolling has to be done with kid gloves. It’s easy to get motorists riled up about it.”