The Virginia government wants to convert all lanes of Interstate 66 inside the Beltway to high occupancy toll lanes for rush hour travel by 2017.

As on Northern Virginia’s other HOT lanes, drivers would pay a toll that rises or falls with the level of traffic congestion. Drivers with at least two passengers could ride free.

Unlike the express lanes on the Capital Beltway and I-95/395, the I-66 inside-the-Beltway version would be HOT only at peak periods.

I-66 map I-66 takes drivers on one of the longest, slowest commutes in the D.C. region.

The plan would dramatically change commuting for tens of thousands of travelers. But it’s only part of a program that is transforming the highway network in Northern Virginia.

The region’s first HOT lanes opened on 14 miles of the Beltway in November 2012. In December, they linked up with 29 miles of HOT lanes on I-95/395. I-66 inside the Beltway would add 10 more miles. But that would be just the first step on I-66. The proposal that Virginia will present on Wednesday to the D.C. region’s Transportation Planning Board also includes adding 25 miles of HOT lanes to I-66 from the Capital Beltway west to Route 15 in Prince William County.

The outside the Beltway plan was first outlined in the summer. It calls for rebuilding the interstate to have three regular lanes and two HOT lanes in each direction by 2022.

The inside the Beltway plan was made public in December, but the documents the state submitted to the planning board add details on the timing and extent of the project.

Another part of the inside the Beltway plan calls for widening the interstate by one lane in each direction for the mile between Fairfax Drive and the Beltway. The widening would be completed by 2040.

Of much more immediate impact would be the transformation of commuting styles in the existing lanes. During today’s peak periods, the lanes are open only to carpools of at least two people in the rush-hour direction. By 2017, under the state’s plan, a driver with only one passenger would need to pay a toll to continue using I-66 for rush hour travel.

VDOT had been planning to increase the High Occupancy Vehicle threshold from two to three persons in 2020. The HOT lanes plan speeds up the timetable.

The HOT lanes rules would be in effect in both directions at rush hours between the Beltway and the Roosevelt Bridge at the Potomac River. Today’s HOV rules apply only for eastbound traffic in the morning and westbound traffic in the afternoon.

Both directions would be free for all traffic at off-peak hours.

That operating style would be a major variation from the other Northern Virginia HOT lanes, and so would the management: VDOT plans to control these HOT lanes, rather than lease them to a private company.

VDOT said the toll revenue would be used to offset the cost of building and maintaining the project. Revenue beyond that would contribute to various programs aimed at finding ways to get commuters out of their cars. That’s always been an important aspect of the HOT lanes theory, if not the practice.

Varying the toll with the level of traffic is a strategy designed to give all drivers a reliable trip, without the stop and go — sometimes, mostly stop — that characterizes many of the region’s commuter arteries. The strategy also helps local governments comply with federal transportation rules. When interstate highway lanes are converted from HOV to HOT, the conversion must not “degrade the facility.” The addition of toll-paying drivers to the traffic must not worsen the travel conditions for the carpoolers.

Virginia hopes to start construction on the inside the Beltway system in 2016. VDOT estimates the cost for setting up the tolling system at $75 million to $100 million. The timetable for opening the tolling system is relatively rapid compared with the region’s other HOT lanes projects. Unlike the others, the 2017 project for I-66 does not involve construction of additional lanes.

Wednesday’s VDOT briefing for the Transportation Planning Board marks the start of one review process for the project. To proceed, it must become part of the region’s Constrained Long Range Transportation Plan. Projects in the plan have known sources of funding. It also will be subject to public comment and an air quality analysis. The planning board would vote on adding the project to the long-range plan in the fall.

The planning board meets from noon to 2 p.m. Wednesday at the Council of Governments board room on the third floor at 777 N. Capitol St. NE.