View of the I-395 southbound High Occupancy Toll lanes near Duke Street in Alexandria. This is part of the 95 Express Lanes. (Linda Davidson / The Washington Post)

Virginia’s high­-occupancy toll (HOT) lanes continue to expand in the Interstate 95 corridor.

Construction kicked off last week along a 10-mile stretch of I-95 in Northern Virginia, where Transurban is extending the reversible 95 Express Lanes from Route 610 to Route 17 near Fredericksburg. The $565-million project will deliver another milestone in the state’s vision to create a network of more than 90 miles of HOT lanes in Northern Virginia by 2022.

The project is one of several projects in a $1 billion deal the state announced earlier this year. As part of the deal, Transurban has also agreed to build a new reversible ramp — a $50-million project — connecting the 95 Express Lanes at Opitz Boulevard to enhance access to the popular Potomac Mills shopping center. And the Virginia Department of Transportation will build and maintain a new southbound auxiliary lane, a $30-million project, on I-95 in Woodbridge to address a traffic bottleneck at the Occoquan Bridge.

Officials say the Fredericksburg extension will increase lane capacity — by 66 percent in the peak direction — along one of the most congested stretches of I-95. When the lanes open in late 2022, carpoolers will be allowed to ride free. Solo drivers can use the lanes if they choose to pay. Even those who choose not to pay can benefit, proponents say, because having more people in the toll lanes should help relieve congestion in the general lanes.

The construction over the next three years will create additional traffic headaches for drivers in the corridor. Construction activity will pick up in coming weeks and months as crews move from installing work zone signs and concrete barriers to building the actual express lanes. There will be lane closures along the 10-mile work zone from the vicinity of Exit 143, Route 610, to Exit 133, Route 17 in Stafford County. Additional work is expected near Exit 148, at the Quantico Marine Corps Base exit, where a new Express Lanes access will be added as part of the project.

“Drivers should be alert to construction vehicles entering and exiting the I-95 median at construction access points in the work zone, and they will observe clearing of trees and brush in the median and grading,” VDOT spokeswoman Kelly Hannon said. “We ask drivers to help us keep travelers and our construction crews safe this summer by wearing their seat belt, obeying the speed limit, and limiting distractions as they travel through the work zone."

Transurban President Jennifer Aument said the project will ensure Virginians have a better commute. More than 100,000 carpool and bus commuters use the 95 and 495 network of express lanes, she said, and the extension will extend the express lanes option to carpoolers in the Fredericksburg area.

“This really builds on what has been a very successful network along I-95 and 495 for a number of years,” Aument said. She said Fredericksburg area drivers who encounter long queues lining up on 95 south of the existing express lanes will experience “immediate relief”.

The congestion created when the express lanes end and traffic merges into the general travel lanes will move 10 miles south, and is likely to continue to be a choke point for those continuing the trip south. Aument said her company is working from operations and design perspectives to ease that hot spot.

In the I-95/395 corridor alone, there will be 50 miles of toll lanes from the Washington line to Fredericksburg, including an eight-mile stretch of Interstate 395 that is currently being converted from HOV lanes into toll lanes. That project is expected to open this year.

Transurban also operates the 495 Express Lanes and is working on an 3-mile extension to the American Legion Bridge. Virginia manages and operates 10 miles of HOT lanes on Interstate 66, inside the Beltway. Nearly 23 more miles of express lanes are under construction on I-66.

All HOT lane users need an E-ZPass. A portion of the revenue will help fund highway improvements and transit.