This stretch of Interstate 66 near Vienna is going to look very different by the time the HOT lanes open. (Nikki Kahn/The Washington Post)

The biggest story on the D.C. region’s highways this new year will be the opening of the high-occupancy tolling system on I-66 inside the Capital Beltway. But this also is the year when the state of Virginia and its private partners plan to start building the HOT lanes outside the Beltway.

According to the Virginia Department of Transportation’s timetable, construction could begin in the fall. The four HOT lanes — two in each direction — could be put into operation in the summer of 2022.

This outside project ultimately will be a much bigger deal than the inside one, despite the many attention-getting controversies over the inner HOT lanes.

Having picked its private partner, a consortium called Express Mobility Partners, the administration of Gov. Terry McAuliffe (D) is feeling pretty good about the deal it’s getting. Virginia Transportation Secretary Aubrey Layne has said repeatedly that taxpayers are getting great terms and that five years from now commuters will start reaping great benefits along one of the region’s most congested highways.

Funding for transit was one of the requirements in the contract. In the context of this deal, transit basically means support for carpools and commuter buses. It doesn’t mean an Orange Line extension.

In fact, one of the few financial limits in the deal requires the state to compensate the private partners if a Metro extension is built along I-66 in the next decade. Given the state of Metro today, I’ll go out on a limb and predict that Virginia is not going to incur any such a liability.

These are some of the reasons McAuliffe and Layne are feeling so good: Express Mobility Partners is responsible for all costs to design, build, operate and maintain the HOT lanes, without any upfront public contribution; the private partners will give the state a half-billion dollars at the financial close this summer as a concession fee, the partners will contribute $800 million over 50 years to build and operate those transit projects, and they’ll give $350 million over the same period to the Northern Virginia Transportation Authority for congestion-easing projects.

So who’s willing to build and operate the four HOT lanes over the next half-century in exchange for the tolls? Do these folks know what they’re getting into making a deal like this?

The companies in the private partnership are Cintra, Meridiam, Ferrovial Agroman US and Allan Myers VA Inc. The main players will be Cintra and Meridiam.

I spoke with Patrick Rhode, U.S. vice president for corporate affairs at Cintra, a subsidiary of Ferrovial, which was founded in 1952 and is based in Spain. Cintra develops and operates toll roads around the world. “We have 27 concessions in 10 countries,” Rhode said.

Among its signature projects is the 13 miles of LBJ TEXpress Lanes along I-635 and I-35E in Dallas. This is a gigantic urban highway system by our region’s standards, but the setup would be familiar to commuters who use the 95 Express Lanes or the 495 Express Lanes, even though there are some differences.

Dallas drivers have the option of traveling in regular lanes that are not tolled. On the TEXpress Lanes, the toll varies based on the flow of traffic, with the goal of letting drivers maintain a minimum speed of 50 mph.

Drivers see the current tolls displayed on electronic signs before entering the TEXpress Lanes. Tolls are collected electronically. Carpoolers and motorcyclists get a 50 percent discount during weekday rush hours.

While I-66 would be the first operation in the Washington region, Rhode said Cintra is confident. “We’re very selective as a company to where we invest,” he said. “We believe that this is very similar to projects we’ve had success on in the past.”

In fact, he described to me a customer model quite similar to what I heard from officials with Transurban, the operator of the other Northern Virginia express lanes: The HOT lanes aren’t necessarily for everyday commuters: Many will use the toll lanes selectively, paying for their trips when they need the assurance of reliable travel times.

He doesn’t see any problem linking the outside-the-Beltway HOT lanes with the inside ones, even though the inside ones will not be part of the Cintra operation. “It’s not uncommon at all,” Rhode said. “It’s seamless to commuters.”

I know many commuters have doubts about all this. Let me hear from you.

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, 1301 K St. NW, Washington, D.C. 20071, or ­email