This photo of the express lanes in Tysons shows the array of signs that confront drivers. (Robert Thomson – The Washington Post)

Your questions about how the new high-occupancy toll lanes work has helped me understand just what a complicated addition they are to the D.C. region’s transportation system.

Questions continue to come in about how the 495 Express Lanes work, and during Monday’s online chat some travelers were asking about the HOT lanes now under construction on I-95 in Virginia.

I-95/395 Express Lanes: “I know that Arlington County voted down the HOT lanes to extend much farther north than the Beltway. It sounds like an awkward arrangement as two different systems will share the same lanes. Doesn’t the state/feds ultimately have control over the median and right of way on a interstate highway. How is a local jurisdiction allowed to veto the project? Would it be in everyone’s best interest for the express lanes to extend to the D.C. line?”

DG: Arlington didn’t exactly veto the HOT lanes plan. The county sued the state over the plan, so Virginia eventually decided to stop the HOT lanes at Edsall Road, before they got to Arlington County.

The Federal Highway Administration approved the plan.

Yes, I do think there’s a potential issue at the north end of the 95 HOT lanes. Drivers who have paid a toll because they don’t meet the HOV3 requirements will have to get out of the HOT lanes where they end, rather than continuing north in what still will be HOV3 lanes.

Arlington was worried that if the HOT lanes continued farther north, they would have created congestion issues for the county. They might also have created congestion issues at the 14th Street Bridge.

Any highway improvement has to end somewhere and those improvements are always likely to generate concerns. Over on the 495 Express Lanes, people are concerned about congestion northbound between the end of the express lanes and up to and beyond the Legion Bridge. But I haven’t seen any evidence of that yet.

[Later in the chat, a traveler responded to that last statement of mine.]

Express Lane Merge:  “You obviously must not drive the corridor during either morning or afternoon rush hours. There is now a regular backup at the northbound merge point every morning (it might have more to do with the soundwall construction and Georgetown Pike interchange improvements, but it’s there), and the Express Lanes regularly back up in the afternoon, sometimes beyond the final gantry that causes an alternate merge in the left lane of the beltway that compounds the traffic heading north into Maryland. The northern merge point of the Express Lanes is an issue!”

DG: I drive that route frequently and on days when I don’t, I check the traffic cameras. Congestion at the north point — congestion caused by the merge as opposed to the regular congestion in that area — is something I haven’t seen. But I’d like to hear from those who have. Write to me at If you include your name and home community, I’ll publish your letter in an upcoming column.

[Meanwhile, my explanation of what’s happening with the I-95 lanes didn’t do it for at least one reader.]

Clarification of what’s being built on 95 South: “I’m more confused than ever after your last answer. We drive from DC to Dumfries(weekends mostly) occasionally and try to take advantage of the HOV lanes which are free now. Will we have to pay to use them in the future?”

DG: Yes. That is, if you don’t meet the HOV3 requirement and don’t have an E-ZPass Flex transponder. The 95 Express Lanes, which are scheduled to be done next year, will charge a variable toll. They’ll work pretty much like the Beltway express lanes. The tolling will be in effect at all times.