Dear Dr. Gridlock:

This is in response to the question that David Kaplan of Fairlington posed in last Sunday’s column concerning the lack of additional traffic because of Mark Center.

I live in the Landmark area. Since Mark Center opened, the traffic volume on the side roads around the Duke Street/Little River Turnpike interchange at Interstate 395 has increased significantly.

It appears that this increase in congestion, in an already busy area, is caused by drivers taking this route to avoid the Seminary Road interchange. I can only assume that this congestion spillover will continue to increase.

— S. Schermer, Alexandria

Faced with a new obstacle, drivers will seek the paths of least resistance. Eventually, these alternatives will become saturated, and the immediate measures taken to ease traffic around Mark Center also will reach the limit of their effectiveness, said Tom Fahrney, who has been working on traffic-improvement plans for the Virginia Department of Transportation.

Dear Dr. Gridlock:

In the morning rush, the gridlock is northbound, while Kaplan is heading south. In the evening, it is reversed. He doesn’t notice the gridlock because he is driving opposite the flow of the heaviest traffic. Lucky dog.

I, on the other hand, drive the full length of northbound I-395 north every morning and the reverse every evening. It is clear that the impact of the new building is significant.

Ordinarily, 395 south during the evening rush sees a lot of entry and exit traffic in the right lanes, but the lanes have traditionally stayed relatively clear going south from the Shirlington merge until it stacked up past Seminary Road. Since the building has opened, traffic is stalled in those entry and exit lanes, and indeed all down the right side from the Pentagon until Edsall Road.

There is no place to go. Our commutes are longer. Shame on the planners of this fiasco.

— Bob Hogue, Springfield

Once the federal base realignment plans were approved, local planners could only play catch-up, which was a losing game. This year and next, some additional short-range improvements will be made around Mark Center. Those include widening the ramp from Seminary Road onto I-395 south.

Fahrney is looking at the worsening congestion in years ahead. He wants the planned HOV/transit ramp from northbound I-395 to Seminary Road as a partial solution, but that won’t be done before late 2015.

Connector in winter

I got this note from a reader during my online chat Monday.

“Dr Gridlock: I take the Intercounty Connector every day and love it. Today [Monday], when I drove it between 10:10-10:20 a.m., I counted five snowplows sitting at the ready by the toll gantries. . . . My question is why? My car thermometer said the temp was 36 degrees.”

Drivers frequently complain about state vehicles along the side of the connector, but they’re almost always complaining about police cars enforcing the speed limit. This was my first complaint about snowplows.

Kelly Melhem, a spokeswoman for the Maryland Transportation Authority, said that even though our traveler’s vehicle registered an air temperature of 36 degrees, the highway and bridge surfaces were still around or below freezing.

“By placing trucks along the ICC, we can provide immediate response and monitor conditions along the entire roadway,” she wrote in an e-mail. “Since this is the first full winter with the ICC open to traffic, we’re building history with the roadway that will allow us to review and tweak our strategy as needed, with safety again being the priority.”

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