Serious rain returns to the D.C. region this weekend, the Capital Weather Gang says. Friday should be the worst of it, but the rest of the weekend rates as “dank and dreary.” That’s not good for fans traveling to the Nationals’ last home weekend of the 2011 season, some meaningful games with the Atlanta Braves, or D.C. United’s game with Real Salt Lake in RFK Stadium at 7:30 p.m. Saturday.

Other outdoor activities this weekend include the National Book Festival on the Mall, Clarendon Day and the SW ArtsFest in Southwest D.C.

Street closings in Foggy Bottom have begun for the IMF/World Bank weekend meetings. Here are some other issues that may challenge your travels through the D.C. area this weekend and beyond.

Metro weekend delays

This is the schedule for maintenance that begins at 10 p.m. Friday and continues through the midnight closing on Sunday.

Red Line: Trains will share one track between the Dupont Circle and Judiciary Square stations during the continuing repairs at Farragut North.

From 9:30 a.m. to 9 p.m. Saturday and Sunday, trains will leave every 10 minutes from the ends of the line at Shady Grove and Glenmont. Every other train from Shady Grove will terminate at Dupont Circle. Every other train from Glenmont will terminate at Union Station.

At all other times during the weekend, trains will leave Shady Grove and Glenmont every 20 minutes.

The last train from Glenmont will leave 11 minutes earlier than usual, at 2:26 a.m. Friday and Saturday nights, and at 11:26 p.m. Sunday.

Add half an hour to normal travel times because of the single-tracking.

Blue Line: Trains will share a track between Pentagon City and Arlington Cemetery while workers upgrade the track structure. Add 20 minutes to your normal travel time.

Orange Line: Trains will share a track between Vienna and West Falls Church while workers replace cross ties and insulators. Every other train will terminate at West Falls Church and return to New Carrollton.

Green Line: Trains will share one track between the Southern Avenue and Naylor Road stations during work on rail fasteners. Add 20 minutes to normal travel times.

IMF/World Bank meetings

These streets around the International Monetary Fund/World Bank buildings will be closed until about 5 p.m. Sunday:

The intersection of 19th and G streets NW closed to northbound traffic; 19th Street and Pennsylvania Avenue NW closed to southbound traffic; 18th Street NW intersections at H and G streets are closed to westbound traffic; 20th Street NW intersections with H and G streets are closed to traffic. Police may also restrict traffic on the streets approaching those blocks.

On the following streets, parking is barred until 5 p.m. Sunday:

18th Street NW from G Street to Pennsylvania Avenue; 19th Street NW from G Street to Pennsylvania Avenue; 20th Street from G Street to Pennsylvania Avenue; G Street NW from 18th to 20th Street; the southern side of H Street NW from 18th to 20th Street.

Till noon Friday, these streets near Constitution Hall will be closed to traffic and parking: C Street NW from 17th to 18th Street; D Street NW from 17th to 18th Street.

Clarendon Day on Saturday

Some Arlington County streets will be closed from 5 a.m. to 8 p.m. Saturday for the annual Clarendon Day festival:

Wilson and Clarendon boulevards between Washington Boulevard and North Garfield Street; North Highland and North Hartford streets where they connect with Wilson Boulevard; North Herndon and North Hudson streets at Wilson Boulevard, and North Highland Street at Washington Boulevard.

The event also has a 10 K race, which will close Wilson Boulevard from Arlington Ridge Road to North Highland Street between 8 and 10 a.m. Saturday. Kent Street between North 19th Street and Wilson Boulevard, and northbound Route 110 from Route 1 in Crystal City to the Rosslyn exit will be closed from 6 to 10 a.m.

Barracks Row Fall Festival

These streets are scheduled to close from 6 a.m. to 7 p.m. Saturday for the Barracks Row Fall Festival in Southeast D.C. near Metro’s Eastern Market station: Eighth Street SE between E and I streets, along with surrounding streets that lead to Eighth Street.

17th Street Festival

This festival just east of Dupont Circle in Northwest D.C. will require closing 17th Street between P and S streets from noon to 8 p.m. Saturday.

Sunfest in O.C.

There won’t be much sun for the rest of Sunfest in Ocean City, which may hold down the traffic the Maryland Transportation Authority had expected on the Bay Bridge this weekend. Sunfest continues through Sunday.

The authority said it will monitor the traffic flow and — if the weather if favorable — go to two-way traffic on the westbound span to ease any eastbound delays.

Hearings on HOT lanes

The Virginia Department of Transportation has scheduled three public meetings this coming week to review plans for the Interstate 95 high-occupancy toll lanes project.

All the meetings are from 5 to 8 p.m.:

Monday: Botts Fire Hall, 1306 F St., Woodbridge.

Wednesday: Waterford at Springfield, 6715 Commerce St., Springfield.

Thursday: North Stafford High School, 839 Garrisonville Rd., Stafford.

VDOT says that oral and written comments will be accepted at the hearings. Comments regarding the project design and environmental analysis can be sent to John Lynch, regional transportation program director, Virginia Megaprojects, 6363 Walker Lane, Suite 500, Alexandria, VA 22310 or to by Oct. 14. (Put “I-95 Joint Meetings” in the subject line.)

New bus in Southwest D.C.

Residents of Southwest D.C. are about to lose the D.C. Circulator bus that operates between the Washington Convention Center and the Southwest Waterfront, mostly along Seventh Street. Instead, they’ll have a new Metrobus, Route 74, which will cover much of the same territory.

The Metrobus will cost more to ride and will operate less frequently than the Circulator, but it’s a better solution than eliminating that bus service. The District Department of Transportation said that the ridership for that Circulator route was too low. Meanwhile, it wants to start a new line serving neighborhoods east of the Anacostia River.

The Circulator’s popularity is based in part on its distinctive branding in the design of the buses and the timetable that schedules bus arrivals every 10 minutes. Metro has more flexibility in adjusting timetables on routes with lighter or heavier demand.

Buses on the new 74 route will operate every 18 minutes during peak hours and every 24 minutes all other times. The 74 buses start running Sunday. The Circulator route is scheduled to end next Friday, Sept. 30.

Pennsylvania Avenue SE

Drivers may want to make plans now for dealing with a traffic restriction on Pennsylvania Avenue SE that is scheduled to start Monday.

The District Department of Transportation plans to temporarily restrict lanes on Pennsylvania Avenue SE between Branch and Southern avenues to complete roadwork on the Pennsylvania Avenue Great Streets project. During this phase, a single lane will be open in each direction on Pennsylvania Avenue.

Traffic between Branch Avenue and 38th Street will be reduced to one lane in each direction starting Sept. 26 and continuing through October. The portion of the project from 38th Street to Southern Avenue will be reduced to one lane in each direction from October through December.

Once the segments are rebuilt, the new lanes will be opened to allow for two lanes of traffic in each direction.

Work will take place between 7 a.m. and 7 p.m. Mondays through Saturdays. Work zones will be expanded as needed, DDOT said. Sidewalks will be kept open, and temporary crosswalks will be set up at intersections.

Traffic delays are likely. DDOT suggested that drivers use alternative routes, which include Suitland Road to Alabama Avenue to Good Hope Road, and Massachusetts Avenue to Minnesota Avenue.

Beltway exit to close

Variable message boards along the Capital Beltway in Virginia are warning drivers about a major change in the traffic pattern coming up around the end of the month along the inner loop.

The left lane exit (49C) to westbound Interstate 66 in Virginia is scheduled to close permanently as construction continues on the high-occupancy toll lanes project.

Watch for some additional traffic congestion at the I-66 interchange immediately after the closing. All inner loop drivers heading to westbound I-66 will then use the right-side ramp, exit 49A, which is being widened to accommodate the extra traffic.