Upcoming delays on I-95

Construction of the 95 Express Lanes is approaching the halfway point, with a planned opening of the new high-occupancy toll lanes in early 2015.

This fall, workers are building bridges and access ramps along the Interstate 95/395 corridor in Northern Virginia. Over the next few weekends, crews are scheduled to place large steel beams to support flyover ramps at the northern and southern ends of the project, which means more traffic disruptions through a work zone that has slowed commuters as well as weekend getaway crowds this year.

The schedule calls for placement of beams over I-95 near Garrisonville Road in Stafford County late Friday and Saturday nights. That will close all lanes of I-95 South, and traffic will be detoured to Route 1. The southbound lane will gradually reopen after 5 o’clock Saturday and Sunday mornings.

I-95 travel tips

Southbound travelers hoping to dodge traffic congestion on I-95 in Northern Virginia know about a couple of options: Route 301 to the east and a combination of Route 29 and Route 17 to the west. These add miles to many trips.

When we talk about how to dodge congestion on long trips, I usually recommend traveling very late or very early, but the worst of the construction disruptions for the 95 Express Lanes occurs very late and very early.

Recently, a traveler on a weekend trip between Northern Virginia and Petersburg wrote to me about her experience: She left Alexandria at 12:45 p.m. on a Saturday and encountered slow traffic — sometimes stopping — through Woodbridge. The speed picked up after that, and there were no further delays.

On the Sunday return trip, she left Petersburg about 11:30 a.m. and was home before 2 p.m. She had no long stoppages, but she did experience some very sudden slowdowns in the Quantico-Woodbridge area.

As always, your experience may very, but watch out in particular for those sudden slowdowns.

Where to turn back?

A reader who has been following plans for the new Metro Silver Line asked why the transit authority couldn’t run four-car or six-car trains on the line so they could fit into the side track just east of the Stadium-Armory station.

This would increase crowding on those trains, he said, but it would reduce the time it takes to get the trains from one end of the line to another.

Both those things would be true. But I hope the days of four-car trains on Metro are gone forever, along with the crowding that resulted. Metro can send 26 trains per hour through the central D.C. tunnel. That’s what it’s doing now, and that’s what it will be doing when the Silver Line joins the Orange and Blue lines early next year.

The trains need to be either six cars or eight cars long to cope with the crowds. Turning Silver Line trains back at Stadium-Armory, rather than at Largo Town Center, would not increase the service through downtown and into Northern Virginia.

Roundabout work

Drivers along Route 15 and Route 50 in the Gilbert’s Corner section of Loudoun County can expect to encounter flaggers between 9 a.m. and 3:30 p.m. weekdays now that the Virginia Department of Transportation is rebuilding the roundabout there to reduce the number of crashes caused by speeding.

The work to adjust the traffic pattern at the four-year-old roundabout should be done by Thanksgiving.

The crews are changing the curb lines, pavement markings and signs. The result will be a single lane on all approaches to the roundabout. The north-south approaches from Route 15 now have two lanes in each direction. The adjustments also will increase the curve on the approaches, which VDOT officials hope will also slow down drivers while making the roundabout navigation simpler for them.

For more transportation news, visit washingtonpost.com/transportation.