Traffic flowed easily along the HOT lanes in the middle of the Capital Beltway when the lanes opened in November 2012. (Dayna Smith/For the Washington Post)

Military strategists say no battle plan survives contact with the enemy, and we sometimes see the same result when the enemy is traffic congestion.

Drivers who use the express lanes in Northern Virginia have noticed lately that the rush-hour tolls have shot up to remarkably high levels. Meanwhile, the traffic in the lanes is not so express, despite the theory that the variable tolls should maintain the travel time.

I’m a fan of these high-occupancy toll lanes, and would like to see Maryland explore the possibility of extending them along the west side of the Capital Beltway and up Interstate 270.

Since the 495 express lanes opened on the Virginia side of the Beltway in 2012, I’ve almost always gotten a trip that’s quicker and more reliable than what I could have gotten in the regular lanes.

But when one electronic sign tells me the toll for a trip from just north of Tysons Corner to Springfield is $29 while another warns of congestion ahead, that’s above my threshold.

Transurban, the company that operates the Virginia express lanes on the Beltway and Interstate 95, believes this is a seasonal phenomenon.

Transurban spokesman Michael McGurk described the heavy traffic and high tolls as “a perfect storm of holiday traffic around Tysons, SafeTrack Surge 11 and declining daylight.”

The SafeTrack maintenance project drastically reduced rush-hour service on the Orange and Silver lines. The Silver Line goes through Tysons Corner, and a little south of there, the Orange Line crosses the Beltway along Interstate 66.

Many commuters probably choose to drive rather than deal with the crowding and uncertain schedules on the two rail lines.

Declining daylight is a factor in congestion, as well, transportation researchers say. As the days grow shorter, commuters are less likely to spread out their daily routines, and this sharpens the peak part of the peak periods.

Transurban offered advice for commuters on the hours when travel in the express lanes on I-95 and the Beltway are likely to be most expensive: between 7 and 8 a.m. and between 5 and 6 p.m. on weekdays. Travel an hour earlier, Transurban said, and the toll could be 33 to 60 percent lower.

Although the high tolls and heavier than normal traffic may pass with the holidays and the SafeTrack project, commuters would have been better off if the state had developed a robust system of commuter buses to take advantage of the HOT lanes, in which buses can travel free. Such a shared-ride system would have dampened the demand for the express lanes among solo drivers.

Now let’s switch scenes to the Arlington County Board, which last week considered a resolution giving qualified support to extending the I-95 HOT lanes north along Interstate 395 to the Potomac River. The Virginia Department of Transportation plans to begin construction in 2017 and to open the express lanes in 2019.

The board’s vote was not a make-or-break moment for the project, but it was interesting because Arlington County had filed a lawsuit against the original version of this plan, which is a big reason the 95 express lanes now stop just north of the Beltway.

This time, county board members voted 5 to 0 to endorse the concept of the HOT lanes extension, but they sought to ensure that reality will wind up matching the concept.

What about the plan changed to win the board’s conceptual approval?

The new plan creates no new interchanges along the extension and has a limited effect on the existing ones.

Another important change is a Virginia state government guarantee that millions of dollars will be spent on programs that let commuters leave their cars behind for trips in the I-95/395 corridor. Those programs haven’t been selected yet, but they’re likely to focus on carpooling, commuter bus trips and filling in gaps along biking and walking routes. There was no such funding guarantee associated with the toll revenue from the 495 express lanes or the 95 express lanes.

Board member Jay Fisette, who introduced the supportive motion on the project, said his qualified backing was based on the evolution of the plan: “When this proposal first came through, this was a very different project. This is a far better project.”

The concerns voiced by board members and community leaders are natural on any big highway project that has a regional impact.

“We just want to know that VDOT is on board to help us through it,” board member Christian Dorsey said of the local concerns.

Among other things, that means gaining a more thorough understanding of the effect the HOT lanes extension will have on traffic along streets at least a half a mile beyond each I-395 interchange — and being ready to help deal with any unforeseen consequences.