Rush hour traffic is backed up along Interstate 66 near the Vienna Metro station. (Nikki Kahn/The Washington Post)

After spending much of 2015 working on Virginia’s effort to rebuild Interstate 66 and add tolls, state Transportation Secretary Aubrey Layne had reached this conclusion: “Everyone may not like every aspect of what we’re planning.”

There’s one statement about the multibillion-dollar, multiphase, multiyear, multi-modal, multijurisdiction program that will draw widespread agreement. After that, accord begins to break down.

Although the overall plan has significant support, anything this complicated also has plenty of skeptics, doubters and flat-out naysayers.

Here’s an incomplete list of what they can pick on: The taking of 11 private properties for the outside-the-Beltway portion of the high-occupancy toll lanes project, the lack of additional lanes for the inside-the-Beltway portion, the possibility that more lanes will be added later, the possibility that the state will finance the project, the possibility that the state will enlist a private partner to finance the project, the uncertainty over the carpool standard needed for a free ride, the exclusion of hybrids from the free-ride category and — oh, yeah — the tolls.

Layne made his summary comment Thursday in Fairfax County during his latest status report for Northern Virginians. Given the potential of misunderstanding and mistrust on all the topics listed above, it was important to the secretary that the project not be seen as “something VDOT sat in a back room and came up with.”

He started with an attention-getting premise. “You have the distinction of being the most congested region in the country,” Layne said. “Doing nothing is not acceptable.”

With I-66 ranking at the top of the region’s congested corridors, he and his transportation team outlined their latest thinking. These are some highlights.

The Virginia Department of Transportation has decided on its “preferred alternative” among all plans and designs under consideration, but the basic idea remains unchanged. Outside the Beltway, I-66 would be rebuilt to have three regular lanes and two HOT lanes in each direction.

However, the latest thinking is to develop some parts of the project in phases. The first phase of HOT lanes construction would stretch 22 miles between the Beltway and University Boulevard in Gainesville. The originally envisioned 25-mile route out to Route 15 in Haymarket could be completed later, as funding allows and as travel demand requires, VDOT officials said.

Another cost-saving change from the initial plan: The existing ramps and bridges at Monument Drive and Stringfellow Road would be retained and converted to HOT lanes access points, rather than rebuilt as interchanges. That rebuilding also could be part of a follow-up phase.

There is space in the median where a transit line could someday run. The project would also include construction of entrance points for the express lanes, improvements at interchanges, new or expanded park and ride lots and rapid bus service. Improvements would be made to bikeways, trails and sidewalks throughout the I-66 corridor.

The decision on whether to publicly finance the project or enlist a private partner probably will be made in December, Layne said. Northern Virginia’s other two HOT lanes systems, the 495 Express Lanes and the 95 Express Lanes, involved private financing and operation through the state’s public-private partnership program.

VDOT said it remains on course to begin construction in 2017 and open phase one to traffic by 2021. There is no estimate yet on tolls for a typical commute.

Layne and the VDOT officials also provided updates on the inside-the-Beltway portion of the I-66 program. That part through Arlington County is a bit less than 10 miles long, but it appears to be just as controversial as the longer stretch outside the Beltway.

The project has this unique feature: The entire highway would be converted to HOT at peak periods. The estimated toll eastbound during the morning rush is $9. During the westbound rush in the afternoon, the estimate is $8. That assumes the state would maintain the two-person standard for a free-ride carpool when the lanes go HOT in 2017.

Although the initial proposal contemplated raising the carpool standard to three in 2017, it now looks more likely that the upgrade won’t occur until the outside-the-Beltway lanes are completed.

That cuts two ways: Carpoolers won’t have to pick up a third commuter for a few more years. But it also keeps more cars on the highway for a while longer. More cars means more traffic, and since the toll rises with the level of traffic, the drivers will pay more while the HOV2 system lasts.

Dr. Gridlock also appears Thursday in Local Living. Comments and questions are welcome and may be used in a column, along with the writer’s name and home community. Write Dr. Gridlock at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071, or e-mail drgridlock@