Metro rail cars are being used to test the Silver Line tracks just west of the Wiehle-Reston East station. (Stephen Barna/Dulles Corridor Metrorail Project)

Monday morning’s highway commute was somewhat lighter than normal, even considering that Monday and Friday mornings tend to be the week’s lightest in the D.C. region. Has vacation season finally arrived?

Travelers may notice more motorcycle and scooter traffic Monday. It’s the annual Ride to Work Day. Most of the day should be sunny, but there is a chance of showers, the Capital Weather Gang says. After Tuesday, the weather should slip into a tranquil, early-summer pattern.

Road work sites will be very active. On Sunday’s Commuter page, I named some of the prime ones on the Maryland side. Metro has some late night work, plus a big Red Line project for the weekend. (See my Sunday column: While Metro looks to bright future, riders’ view of today’s conditions remains cloudy.)

The Nationals return home Thursday and play at Nationals Park through the weekend. D.C. United will play at 7 p.m. Saturday at RFK Stadium.

Join me at noon Monday for a new discussion of the region’s traffic and transit issues.

HIGHLIGHTS: Metro weeknight schedule | State of traffic | Silver Line | New York Avenue | Maine Avenue | Rock Creek Parkway | Metro weekend schedule | 95 Express Lanes

Metro late-night schedule
Metrorail has work scheduled on all five lines through Thursday night, resulting in delays of about 10 minutes where trains share single tracks around work zones. These are the work zones.

Red Line. After 8 p.m., between Dupont Circle and Van Ness. After 10 p.m., between Takoma and Forest Glen.

Blue Line. After 8 p.m., between Van Dorn Street and Franconia-Springfield. Delays approximately 10 minutes.

Blue, Orange lines. After 10 p.m., between McPherson Square and Smithsonian.

Green, Yellow lines. After 10 p.m., between U Street and Georgia Avenue.

The state of traffic

During my online discussion last Monday, many drivers said they thought traffic in the D.C. region got worse in late May and early June and wondered why. The routes they take are widely scattered, and their bafflement suggested they weren’t encountering the lane closings or crash scenes that would make the causes obvious.

One commenter suggested a combination of elements. Some schools haven’t closed yet, it gets light earlier so some commuters may be starting earlier (so they can go home earlier) and people are generally more active outside.

David Buck, a spokesman for the Maryland State Highway Administration, had a very credible notion on this. He referred to mid-May/mid-June as a “transition period,” an overlap when some vacations have begun to bring travelers into or through the D.C. area while local schools remain in session.

The really sharp declines in local commuter traffic don’t show up until July and August.

Trouble spots

One reason I asked Buck for his view was that some drivers said they were experiencing more traffic on the inner loop of the Capital Beltway in Maryland near the Woodrow Wilson Bridge. Buck and I believe there’s something to this, but neither of us can cite a specific cause, such as road work.

Here again, we suspect volume: a combination of local commuters and warm-weather travelers along the East Coast’s major north-south route.

Other commuters complain about delays as they drive into Washington on the Memorial Bridge, but they suspect the culprit is a traffic signal at Lincoln Circle and 23rd Street NW.

Some trouble spots never really go away. It’s just a question of when they’re bad and when they’re worse.

For morning commuters, those include the outer loop of the Capital Beltway through Silver Spring; D.C. 295, I-295 and the Suitland Parkway near the 11th Street bridge, the junction of the Baltimore-Washington Parkway and Route 50; I-395 near the 14th Street Bridge; and I-66 through the Manassas and Fair Oaks areas.

Silver Line
The Dulles Metrorail project has extensive work underway along I-66 in the Falls Church area, Routes 123 and 7 through Tysons and on Route 267 west to the Silver Line’s phase one terminal at Wiehle Avenue. The goal is to complete construction by the fall. Following are a few highlights.

Interstate 66 East. Night lane closings Monday through Sunday on eastbound I-66, between Great Falls Street and Route 267, for removal of temporary traffic barriers and installation of permanent guardrails.

Dulles Connector Road (Route 267) East. The left through lane of the eastbound Dulles Connector Road, between Magarity to Idylwood roads, will be closed throughout the week during daytime hours for removal of traffic barriers and installation of guardrails.

Wiehle-Reston East station. Lanes on both sides of the Dulles Toll Road and Dulles Access Highway will be closed near the station at night this week.

Route 123 (Chain Bridge Road). Grading and traffic signal work near the Tysons Corner station will close lanes on Route 123 South. Tysons Boulevard and Galleria Drive will also have lane closings this week. Grading work also will close the right lane of southbound Route 123 during the day between Scotts Crossing and the entrance ramp to the Capital Beltway.

Route 7 (Leesburg Pike). Installation of sidewalks and the foundations for light poles and traffic signals, plus work on the roadway and the station pedestrian bridges will require day and night off-peak closings in spots on both sides of Route 7 in the Tysons area throughout the week. This also will affect streets that intersect with Route 7.

New York Avenue bridge
Watch for lane closings this week on the westbound New York Avenue NE bridge over the Anacostia River. The westbound right lane will be closed from 9:30 a.m. to 3:30 p.m. and the two westbound left lanes will be closed from 8 p.m. to 5 a.m. Crews will be repairing the bridge.

Maine Avenue
Watch for lane closings on Maine Avenue SW near the 14th Street Bridge. The federal road project includes milling out the asphalt, repairing the base concrete and paving, which will temporarily leave lanes uneven.

Between 9:30 a.m. and 3 p.m., expect single lane closings on both sides of Maine Avenue. At least one lane will remain open in each direction.

Rock Creek Parkway
Expect single lane closings on southbound Rock Creek Parkway between Beach Drive and P Street for guardrail and street light work from 9:30 a.m. to 3:45 p.m. weekdays. And there will be single lane closings on northbound Rock Creek Parkway between P Street and Beach Drive for street light work from 9:30 a.m. to 3:45 p.m.

Pedestrians will be detoured from the Rock Creek trail between 9:30 a.m. and 3:45 p.m. to complete electrical work near Massachusetts Avenue.

The National Park Service says the work should be done by late summer or early fall.

Arlington Boulevard interchange
The Virginia Department of Transportation will close lanes on both sides of Arlington Boulevard (Route 50) between 10th Street and North Rhodes Street this week for the long-term reconstruction of the interchange.

Watch for westbound closings from 6:30 a.m. to 3 p.m. weekdays and eastbound closings from 9 a.m. to 5 p.m.

Rockville Pike tunnel
The Montgomery County Department of Transportation will host a meeting Tuesday to discuss the plan for a pedestrian and biker tunnel under Rockville Pike between Walter Reed National Military Medical Center and the Medical Center Metro station.

The 7:30 p.m. session will be held at the BCC Regional Services Center, 4805 Edgemoor Lane, near the Bethesda Metro station.

The $68 million project will be funded by the federal government because it is meant to help ease the extra travel generated by the federal base realignment program at the medical center.

Work will include construction of the tunnel, new entrances to the Medical Center station on the Red Line and a bank of underground elevators.

D.C. Circulator meeting

On Tuesday, the D.C. Department of Transportation plans to host another of its semiannual forums to discuss the DC Circulator bus system. This one is scheduled for 6 to 8 p.m. in the Studio Theatre, First Floor Lounge, 1501 14th St. NW, near Logan Circle.

These are informal sessions where people can ask questions about the current and future city bus system and offer suggestions about improvements or alternative routes.

Reston repaving

Starting Thursday, the Virginia Department of Transportation plans to mill and pave almost 4 1 / 2 miles of Fox Mill Road (Route 665) between Lawyers Road and Waples Mill Road in Reston. Drivers will encounter alternating lane closings from 9 a.m. to 3:30 p.m. weekdays for about five weeks.

Because this section of Fox Mill Road is two lanes and narrow, VDOT asks drivers to avoid the work zone and use alternative routes during the work hours to avoid the congestion.

Metro weekend track work
The major event for this coming weekend: Between 10 p.m. Friday and the rail system’s midnight closing Sunday, free shuttle buses will replace trains between Rhode Island Avenue and the end of the Red Line at Forest Glen. The Brookland, Takoma and Silver Spring stations will be closed. At Fort Totten, the Red Line platform will be closed.

A work zone on the Orange Line will mean extra travel time between Landover and New Carrollton. There is no scheduled work this weekend on the Blue, Yellow or Green lines.

95 Express Lanes project
The Virginia Department of Transportation will continue closing the High Occupancy Vehicle lanes on I-395/95 over the weekends through July 14 for construction of the 95 Express Lanes.

During the day, the HOV lanes will reopen in both the northern and southern sections, with a small portion closed in the middle near the Springfield-Newington area where crews will be working.