Drivers on southbound I-95 near Springfield have a close view of lengthy work zones for the 95 Express Lanes project. (Robert Thomson/The Washington Post)

[This post has been updated.]

Traffic in the D.C. region is relatively light because so many commuters are taking their summer vacations, but this also is the time when the highway departments crank up their roadwork programs.

Here are a few areas of special concern.

I-695 near Third Street Tunnel. This District Department of Transportation project, which got the attention of many drivers last week, entered its second phase over the weekend. In this phase, drivers will find the right lane closed on the westbound side of the Interstate 695 approaching the Third Street Tunnel. Meanwhile, the first phase is still underway: Till Aug. 10, the left-most lanes on both sides of I-695 near South Capitol Street are scheduled to be closed.

The third phase, from Aug. 11 to Aug. 31, will close the right eastbound lane from the South Capitol Street exit to Sixth Street SE.

DDOT is building structures for variable message boards that will hang over the freeway. Because of the nature of the work, the lanes must be blocked for long periods of time, said DDOT spokesman Reggie Sanders. It’s not safe or practical to take down the work zones for rush hours, or do the work only at night, he said.

I-66/Route 50 ramp. DDOT plans to close the Route 50 West ramp on the outbound Roosevelt Bridge (I-66) between 8 a.m. and 3:30 p.m. through Aug. 19 while crews repair the ramp. Drivers bound for Route 50 West should continue to Lee Highway, then to Fort Myer drive and onto Route 50.

11th Street SE. For work that’s part of the 11th Street Bridge project, DDOT plans to close 11th Street SE between M and K street from 9:30 a.m. to 3:30 pm. on Thursday. Then it will be closed again at 8 p.m. Thursday and the closing will continue till 5:30 a.m. Tuesday. Workers will complete the installation of bridge girders over 11th Street.

Northbound 11th Street traffic will be detoured via M Street to Eighth Street, then onto G Street and back to 11th Street. Drivers heading south will be detoured to I (Eye) Street, then onto Eighth Street and M Street, then back to 11th Street south of M Street. The 11th Street ramp to westbound I-695 will remain open.

Resurfacing on Capital Beltway. The Maryland State Highway Administration has begun a resurfacing project on both sides of the Capital Beltway between D’Arcy Road, north of Route 4, and Arena Drive in Prince George’s County. The work along this very busy 3.5 mile section is scheduled to be done by late fall.

Weekend work, including lane closings, will take place through early fall, but no weekend work will be permitted during Redskins home games, the SHA said.

Also, crews will close one lane on weekdays between 9 a.m. and 3 p.m. and two lanes, overnights, Sundays through Thursdays, between 9 p.m. and 5 a.m.

Arlington Boulevard interchange. Virginia drivers are very familiar with the long-term rebuilding of the Arlington Boulevard/Courthouse Road/10th Street interchange. Monday through Friday, watch for closings on westbound Arlington Boulevard from 6:30 a.m. to 3 p.m. and on the eastbound side from 9 a.m. to 5 p.m.

Mark Center/Seminary Road. The Virginia Department of Transportation announced that work is done on a set of projects intended to ease traffic around the Mark Center, the site off Interstate 395 where many military workers were relocated as part of the federal base realignment.

These projects included construction of additional turn lanes from Beauregard Street, more access lanes to I-395, wider intersections and more pedestrian safety enhancements around the center on Seminary Road.

Late this year or early next, construction is scheduled to start on the I-395 Transit Ramp, to connect the HOV lanes with Seminary Road. This is the biggest of VDOT’s traffic-easing projects in that area and is scheduled to be done in late 2015.

Columbia Pike. The pike is scheduled to close between South Quinn Street and South Orme Street from 9 p.m. Friday till 4:30 a.m. Monday, the Virginia Department of Transportation said. During that time, workers will place steel beams for the new northbound Washington Boulevard bridge.

Columbia Pike traffic, including pedestrians and bicyclists, will be detoured to a temporary signal at Washington Boulevard.

Northbound traffic on Washington Boulevard heading for westbound Columbia Pike will be detoured to the Second Street South interchange and then back to Columbia Pike via South Courthouse Road. Southbound Washington Boulevard heading to eastbound Columbia Pike will turn left at the temporary signal on Washington Boulevard and follow the detour back to Route 244. South Queen Street will be closed at the intersection with Columbia Pike.

The Washington Boulevard Bridge replacement is scheduled to be done in summer 2015.

95 Express Lanes. The project likely to have the biggest impact on traffic all summer and into the fall is the construction of the high-occupancy vehicle lanes along 29 miles of I-95/395 between Edsall Road, just north of the Beltway, and Garrisonville Road to the south. See a pdf with the full list of all this week’s lane closings.

Throughout the summer, watch for: extensive lane closings and delays at off-peak hours day and night, occasional full closings of I-95 and overnight detours, slow-moving trucks entering and leaving the work zone in the median, reduced access to shoulders.